The phrase "Red Alert" comes from the naval tradition of "General Quarters" ("Action Stations" if you're British), where a ship prepares for battle. Much of the procedures are the same. The alert is sounded by a drum or over an intercom. Off-duty sailors report to their stations, cannons are loaded, and the decks are cleared of non-essential items. On modern ships, lights flash, klaxons sound and all watertight doors are closed, thus if the ship is holed the leak is contained. BREET BREET Ah, great.. See Red Alert right away, the Wiki's gone on Self-Demonstrating Article mode. BREET BREET GENERAL QUARTERS. Often accompanied with This Is Not a Drill.
In a Rescue show, or any film with an emergency service like the fire department, there is a variant of the alert that can be called the Emergency Squad Scramble. where the heroes are at their base and the dispatch call sounds. Suddenly the base explodes with activity as the klaxons sound and the dispatcher comes over the PA system with the essential information. Meanwhile, the rescue heroes move quickly, often going down sliding poles to the garage, calmly to suit up and board their vehicles with utter professionalism. Then with the vehicles' rotating lights flashing and sirens sounding, the production's theme music plays the heroes go full speed to the emergency.
This variant also occurs with fighter squadrons before or during a Fighter Launching Sequence . This often includes a running variant of the Power Walk that can be called the Scramble Run where the pilots, are seen sprinting to their fighters in full flight gear.
If this precedes a Boss Battle, it's a Boss Warning Siren.
Now, keep in mind, this is not to be confused with Command & Conquer: Red Alert, nor with Last Alert (known as Red Alert in Japan), nor with the Red Scare. Nor does it have any particular relation to any of the Transformers characters named Red Alert (WOO WOO WOO WOO). But it is similar, however, to Defcon Five. Err...one. And to Red Filter of Doom.
Understand? Good. Let's move out.
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The Macross franchise (and presumably Robotech), play this more realistically, with General Quarters and condition levels rather than the klaxon and red light.
Sergeant: Sir, yes, sir! Red alert! All civilians fall in position now!
Sev Trek: Pus in Boots (an Australian CGI spoof of Star Trek: The Next Generation). The ship goes to Red Alert, but it's so loud no-one can hear the captain's orders. But they only did it to make Lt. Barf happy anyway.
Master and Commander has a scene where a middie on night watch, suspects an enemy ship is nearby in the fog. Uncertain, he still calls "We shall beat to quarters!". We then see the Napoleonic War version of a ship going into Red Alert and the midshipman's decision proves most prudent as the ship is fired upon and the crew is ready for battle.
In the Cruise version of The War of the Worlds, the walkers have a siren call. This may have been borrowed from the Journey to the White Mountains books, where the walkers would signal out a siren warning call as they approached.
Crimson Tide depicts the captain of the Alabama ordering back-to-back drills for "Battle Stations, Torpedo" and "Battle Stations, Missile" while a very real fire is being fought in another compartment. The climax of the film occurs with the crew at Battle Stations, Missile.
In The Thrawn Trilogy, Pellaeon explains to Grand Admiral Thrawn that the wing commander of the scout ships is fairly certain he eluded pursuit, but that he ordered the sentry ships to yellow alert anyway. Thrawn opines that if they were from the Rebellion (as he insists on calling the New Republic), the ships didn't lose their pursuers. Pellaeon asks if they should go to red, to which Thrawn remarks "There's time."
Assault at Selonia has Han trying to fly a horribly-built Selonian ship. Nearly all the lights on the control panel are green, but that's not good - for Selonians, red is positive, green is disaster. It's noted the reason for this is because Selonian blood is green, as opposed to human red.
Honor Harrington has the General Quarters (GQ) alarm. While the default sound that plays over the speakers is a harsh buzzer, some navies allow captains to choose their own sound for the "we're going to attack someone soon" variant. The "oh crap we're being attacked without warning" variant, however, remains the normal, recognizable, harsh wail.
In the book The Andromeda Strain, the noise of the sirens going off when areas become contaminated is so loud that it they have to ask someone to turn it down so they can communicate. This tends to highlight the fact that the base systems were not tested properly. This is a major Real Life problem, if a system is not designed correctly.
The name of this trope comes from the Red Alert in Star Trek. Over the many series Star Trek had accumulated many variants:
Yellow Alert - When the ship is approaching a potentially dangerous situation.
Double Red Alert - Extreme and immediate danger, e.g. a bomb on board is about to explode.
Blue Alert - The ship is about to enter planetary atmosphere (on Voyager) or about to use its cloaking device (on Deep Space Nine). or is experiencing a life support failure (on Next-Gen). Possibly meant as a general "this might feel weird/we may experience some turbulence" warning.
The USS Prometheus also used Blue Alert for its Multi-Vector Assault Mode.
Grey Alert - The ship is running out of fuel and is rationing power to a bare minimum (AKA Condition Grey)
Tactical Alert - The same as Red Alert, and in fact its ancestor. (In the early years of Starfleet, the first Enterprise's systems were not exactly optimized; Red Alert was as much an optimization of emergency systems such as hull plating polarization, allowing said systems to power up in seconds rather than minutes, as it was a warning for the crew.)
When Reed wanted to create a new emergency protocol that would improve on Tactical Alert, Trip dubs it "Reed Alert".
General Quarters, bringing this full circle.
There was also a rarely used "Condition Green" which was a distress code to alert the receiver that the landing party had been captured. Given how often it happened, you'd think it would get heard more often. One reason why it wasn't was that it was specified to mean "The landing party has been captured, but don't take any immediate action!".
Also famously parodied in MAD Magazine:
Spock: Call for General Alert. Kirk: Paging General Alert! Paging General Alert! Spock: This is no time for joking around, Captain. We have a major disaster here! Kirk: Is that so? Then have Major Disaster report to the bridge - at once!
In Star Trek (or at least the later series), however, the use of low lighting is somewhat justified, as it means that all the little light-up buttons on the control panels show up better, and means that the light won't reflect off the glass surfaces.
Star Trek: Voyager. In "Year of Hell" Neelix is made a security officer and is being his usual annoying self to the Chief Security Officer, Mr Tuvok.
“We're just about done rebuilding the internal security sensors, and we're just about to program the audio signal. Do you want it to say, ‘Intruder alert’ or do you want it to say something more dramatic like ‘Warning – intruder alert!’ or ‘Intruders among us! Danger! Danger! Intruders among us!’?
Played straight on Babylon 5, though notably, while the alarms are sounding loudly throughout the station, warning the station's occupants to seek shelter and the pilots and security guards to prepare for battle, the command center itself is devoid of the alarms and lights. This is to help the command crew avoid any distractions or hindrances to communication, particularly since they're the ones who start the alarm to begin with. Worth noting how the command crew reacts to the Red Alert changes over time, probably as they become more experienced with such situations. In one second season battle, they have to close the blast doors covering the command center's picture window just in time to avoid getting a piece of debris sent flying into them. In the third season, as soon as a battle starts, they immediately shut the blast shield (and sure enough, midway through the battle, a crippled enemy fighter crashes into the shield hard enough to cause the internal bulkhead to buckle.
Averted and then played straight in the first and second seasons of SeaQuest DSV. The original featured a rather low-key alarm klaxon and the 1MC call "General Quarters, all hands to battle stations," along with stock shots of watertight hatches sealing throughout the boat. The second season played the trope to the hilt, adding in lots of flashing red lights and making the siren painfully loud.
Red Dwarf parodied the hell out of this trope and played it for laughs most of the time,
The first example kicked off with an exchange highlighting how pointless it was in their circumstances:
Rimmer: Go to Blue Alert. Lister: Why? There's no one to alert, we're all here. Rimmer: I would just feel better if we were all on our toes because we were all aware this is a blue alert situation. Lister: We all are on our toes... (and so on)
Rimmer: Go to Blue Alert. [A blue lightbulb at the back of the ship starts flashing silently ] (Some time later) Rimmer: Step up to Red Alert. Kryten:[dead serious] Sir, are you absolutely sure? It DOES mean changing the bulb!
What do you get combing Red and Blue Alert? This:
Holly: Purple Alert! Purple Alert! Lister: What's a Purple Alert? Holly: Well, it's worse than a Blue Alert, but better than a Red Alert. Kind of a Mauve Alert...
In the first season of the revived Doctor Who, the Doctor tells Rose that the interstellar color for danger is mauve, and most alien species consider humanity's penchant for red positively camp.
The Doctor: Oh, the misunderstandings - all those Red Alerts, all that dancing.
UNIT in particular has been shown to have a penchant for red, employing "Red Alert", "Code Red Sontaran", and "Ultimate Red Alert'' in season 4.
The TARDIS has what could be considered a type of Red Alert, the cloister bell, which rings to signify a galactic disaster. I.e the end of the universe.
The French-Canadian TV show Dans une galaxie près de chez vous poked fun at this numerous times, with such alerts has "Yellow Alert with suspenders and brown socks" "Purple alert with a ketchup stain" etc... One episode reveals that the ship's crew carries a binder explaining the meaning of each and every alert.
Felix Gaeta: Action stations, action stations. Set Condition One throughout the ship. This Is Not a Drill.
The series prided itself on being more like a real ship, with accurate (or at least believable) use of jargon, than other sci-fi series. Three vital pieces of information into three short sentences; even if it wasn't accurate, it would probably still be a very efficient system. An aversion of Defcon Five — in naval parlance, 'Condition One' is sealing all compartments in full battle-readiness (as cited in the second paragraph of the trope's main body), so it's a correct use of jargon.)
"...to say nothing of the guards' color codes, which include Red Standby Alert (apparently meaning stand around and do nothing), Red Mobilisation (wander around outside the house), and Blue Mobilisation (allow the President and his daughter to escape in a vintage car accompanied by two terrorists)."
At around the same time, Chappelle's Show did a similar gag. This was extended in the Deleted Scene on the DVD, where after several color combos and unusually specific shades, it ended in "The color of these shoes".
Briefly featured in the short-lived alien invasion show Threshold, when the heroes have reason to believe their secret base has been compromised: in addition to the flashing red lights (no klaxon), every regular ceiling light in the building is extinguished and replaced by strobes for no apparent reason.
Parodied in Get Smart; they have Red Alert, but they also have things like "Magenta Alert" and "Blue Alert".
Horatio Hornblower: This being a miniseries in the naval setting, they use "beat to quarters" quite a lot when they are supposed to prepare for a battle at sea.
JAG: The trope is seen in several episodes in the contemporary U.S. Navy sense.
UFO. SID (Space Intruder Detector), SHADO Control and Moonbase all call them whenever a UFO is detected, so it happens on an average of once per episode.
In The Party Zone, when the "Big Bang" jackpot is lit, every light on the playfield turns red.
Final Fantasy XIII plays with this trope and Colour Coded For Your Inconvenience - First an intruder alert causes Code Red, which later escalates to Code Green, and after the prisoners escape to Code Purple. Hope wonders aloud what the heck it all means, and then it's completely lampshaded when Colonel Nabaat starts having her epic Villainous Breakdown, shouting "This means we have a Code Blue! Or maybe Code Yellow. If it was Code Orange that would mean...?" But then Primarch Dysley puts an end to it and remarks that "Desperate times demand flexibility: [beat] ''CodeWhite!"
Half-Life: The Black Mesa Facility would like to inform you that pressing the alert button as a joke is not OK, Dr. Freeman. (Not real dialog, just a joke since you can turn it on and piss people off, and later on it is on by default and you can turn it off For the Evulz).
Half-Life 2 does something similar: After disabling some huge thumpers and getting bugbait to control antlions, one of the Combine Bunkers has an alarm going off. Inside, there's a red button that you can push to turn it off.
In Star Trek: Armada II, alerts contain a different approach, Green alert is were a ship will not attack unless given a strict order to do so (This includes not firing back), Yellow alert will have ships fire at enemy ship's and stations if fired upon, Red alert (Default) has ships attack enemy ships and stations if there in range
In Star Trek: Bridge Commander, you can order Saffi (your first officer) to set the ship's alert status. Green alert is shields and weapons offline, yellow alert brings up shields to 100% power for protecting the ship from minor hazards (nebulae, etc.) and red alert brings up shields and weapons.
Star Trek Online features condition red when the player engages an enemy, both in space and on away missions which prevents the player from performing non-combat actions such as full impulse.
The Crusader series of video games bring the trope off of ships and into the world at large. Whenever the alarm goes off, big red bulbs light up (and some spin, like old-style police flashers), klaxons sound, and a bland female voice says things like, "Code Red!" Oddly, nine times out of the ten the Silencer, usually the cause of the Red Alert, can shut it off by tapping a switch on the wall.
Used reasonably in the Escape Velocity series: a warning alarm sounds when a hostile vessel turns its attention on you - and then promptly shuts up, letting you frag the baddies and/or get the heck out of Dodge as appropriate. (If you have an IFF Decoder, you may also get to see the enemy vessel's dot turn red at this moment.)
Similarly, in the X-Universe series, when a hostile ship comes within about 10 kilometers, you hear a single bleep, then the background music changes to the battle soundtrack.
The Evil Genius video game has three alert levels: Normal (green button, normal duties), Warning (yellow button, everybody is armed and ready), and Danger (red button, everybody is armed, ready, runs, and fires at will). Warning and Danger both cause a klaxon to sound continually in the background. This gets annoying really fast, especially at Yellow Alert. All you want is for your minions to walk around armed, in case enemy soldiers show up. So why do you have to keep listening to that annoying klaxon? There is, fortunately, a glitch, where if you double-tap the button in rapid succession the klaxon stops.
Bosconian features a "CONDITION" indicator. If it's "GREEN", that means no enemies are attacking, but it will eventually change to "YELLOW" ("Alert! Alert!"), and you will have to destroy one of the hexagon-like space stations to get it back to "GREEN". Condition "RED!!" (as it appears in-game) only appears if you take too long to complete a stage. During this time, the enemies attack relentlessly, making more likely for you to lose a life.
In Halo 3, when a Scarab is about to explode, a submarine klaxon type sound is heard. The same sound is heard when destroying the large artillery emplacements in Halo: Reach.
At the beginning of Halo: Combat Evolved, when Capt. Keyes is convinced that there's no way to sneak past the Covenant battle group stationed at Installation 04, he orders the Pillar of Autumn brought to "Combat Alert Alpha". Klaxons sound throughout the ship, the crew and Marine complement get to their stations, and the cryogenics bay thaws out the Master Chief.
In Touhou, the nuclear-powered final boss of Subterranean Animism, Utsuho Reiuji, is unique in that she announces her spellcards not with the generic noise and Super Move Portrait Attack, but with sirens and CAUTION scrolling across the screen.
Rock Raiders players could sound "Action Stations" if a monster or slimy slug showed up, which caused any armed Rock Raiders to start attacking the critters in question. It also sounded automatically if a building was damaged.
The final non-Zero-Effort Boss boss of Gradius Gaiden has no background music. Instead, you're treated to several minutes of emergency klaxons.
A subtle example: in XCOM: Enemy Unknown, every time abduction sites are located, or a UFO is detected, a small warning alarm goes off (code yellow). When a terror site occurs, a louder, more insistent alarm is trigger (code red).
Space Quest 1 and its VGA remake start with Roger Wilco waking up from a nap in the janitor's closet on the starlab Arcada, finding too late that the ship has been invaded by Sariens and the ship will self-destruct in 15 minutes.
In the VGA remake, there are two electronic signs that say "Red Alert". You can smell and taste them with the extra cursors, with hilarious results.
Smell: "You notice a smell common to electronics which haven't had power applied to them in a long time."
Taste: "Boy, was that a bad idea! Your tongue now bears the residue left behind by adventurers who, like yourself, have felt the need to press various and sundry organs against the sign."
In a Harvey Birdman, Attorney at Law episode that parodies the Homeland Security color alert system, code red is followed by code blackwatch plaid, which is then followed by an alert consisting of the cover art from Rush's Moving Pictures album.
To completely ruin the joke, there is a Transformer named Red Alert. The meme comes from a Red Alert toy that would say his name followed by a brief siren if you pushed a button. "Red! Uh-lurt! Woo woo woo woo!"
In Metalocalypse, the Tribunal calls a "Purple Alert" when Nathan Explosion is elected governor of Florida. It's extremely irritating.
The Herculoids episode "Prisoners of the Bubblemen". After Dorno frees Zandor and Tarra, the enemy leader orders "Sound the alarm" and a tower starts a lighthouse-like rotating red light at its top, with a whooping siren accompaniment.
Episode "The Sea Haunt". As the title creature climbs onto the deck of the ship the captain tells a crewman to "Sound the alarm! All hands on deck!", and an alarm bell starts ringing.
In both "Arctic Splashdown" and "The Robot Spy" there are "scramble alerts" at Air Force bases, with jets taking off. In "The Robot Spy" the Duty Officer actually says he's going to call a "Red Scramble" and pushes a Big Red Button with the label "Red Alert".
Britain's version of the the DEFCON system was the BIKINI alert system, which operates in this manner. The colour scale consists of (in ascending order) White, Black, Black Special, Amber and Red. It was replaced by "UK Threat Level" system in 2006, which isn't a color-coded system.
The HANDEL system, which was the UK's Nuclear Attack warning system and companion to the BIKINI states, also had this, with "Attack Warning Red" being the cue to set off the Four Minute Warning. Other colours included "Fallout Warning Black," which meant imminent fallout danger, "Fallout Warning Grey" which was for expected fallout and "Attack Warning White" which was the all clear.
Truth in Television: The United States Department of Homeland Security Terror Alert Level, which is on yellow by default. There are two lower levels (Blue and Green), but they have never been called. Orange Alert has been called a few times, but Red Alert has only been called once, after some idiot terrorists tried to sneak liquid explosives onboard airplanes coming in from England and have caused problems for millions of air travellers since.
Shortly after the terror alert system was first created, Jay Leno did a bit on The Tonight Show spoofing it. The final mock colour alert was "White with a black dot," which meant "Terrorists are impersonating Jay Leno."
The system was also spoofed by Stephen Colbert in the opening on one episode of The Colbert Report. Colbert reported that the alert level had been raised to brown, because "somebody spilled coffee on the chart."
Another spoof, this one from Saturday Night Live: a color-coded system is introduced and explained, but all the colors are virtually-indistinguishable shades of white (white, off-white, bone, putty, etc.)
Also mocked by comedian Ron White. He says if it were up to him, there would be two levels of alert: "Go find a helmet", and "Put on the damm helmet".
Some real-life fire alarms sound like red alert klaxons.
HMNB Devonport, in Plymouth, UK, tests the Nuclear Accident Siren every Monday morning at 1130. This is a massive, WWII-esque 'The bombers are coming!' alarm that can be heard about a mile away in parts of the city and is a little unnerving if you haven't heard it before or aren't expecting it.
Residents of the midwestern United States are no doubt intimately familiar with tornado sirens, which are designed to emit an amazingly loud wailing sound when a tornado is spotted nearby, warning everybody to seek shelter immediately.
Although all it usually does is either prompt people to run outside and see the funnel cloud or to sit inside and turn the TV to the local news to see how close it is.
Military installations will often use a similar system, which include the added convenience of a distinctive alarm reserved for incoming enemy attack.
Modern US Navy warships actually have several alarms, which all sound distinct so you can tell precisely which emergency you are in. They are the Collision, Chemical, Flight Crash, and of course General alarms. Each alarm is usually followed by an announcement re-enforcing the alarm and giving specific directions. Additionally, a brass bell is rung over the announcing system in the case of a fire, flooding, or other damage to the ship, with directions on where to go to fight the casualty.
For example: *GENERAL ALARM SOUNDS* "General Quarters, General Quarters, all hands man your battlestations. Proceed up and forward to starboard, down and aft to port. Reason for General Quarters is: (missile inbound/torpdeo sighted/alien attack/drill/etc)."
For a fire: *BELLS SOUND* "Fire, fire fire! Fire in compartment (compartment number), (compartment name). Away the at-sea fire party, provide from Repair 5. All hands not involved, stand clear of the scene."
SimCity 2000 has a loud klaxon that goes off in the event of a disaster, whether selected by the player or automatically started in-game. There's an option for "No Disasters", and a special track is called "Disaster Decision" in some versions.
Emergency Squad Scramble Examples:
Films — Live-Action
Ghostbusters. The first time a call comes in, Janine hits the siren and the title characters do a Emergency Squad Scramble to get dressed and take off in the Ectomobile.
Justified in that they set up shop in an old, abandoned, apparently-still-functional, yet remarkably cheap firehouse. The confused look on everyone's face for about 5-10 seconds after the bells start going implies that, in-universe at least, this wasn't part of the plan and Janine just felt like doing it.
The surprised look is because it's their first job ever. The comedy comes from the fact that Janice had just assured the client they'll be very discrete — cue flashing lights and sirens.
Code Red had a really dramatic Emergency Squad Scramble with a large firehouse crew and fleet, including the Fire Chief in his own car, as shown here.
London's Burning usually featured a similar but lower-key scene centered on one or two fire engines.
Emergency! had the distinctive Quick Call system where each station has its own series of tones to indicate it is being called up and a klaxon that sounds to confirm the Station 51 is being deployed. The dispatcher would then, along with destination info, specify "Squad" for the medics or "Engine" for the fire engine, or "Station" for both. Once, a very tired John Gage mixed them up when awakened and climbed on the engine rear by mistake, with DeSoto yelling behind him "IT'S NOT FOR US!"
In S.W.A.T., the opening credits started with the team responding to an alert over their radio by gearing up and boarding their police van. As seen here.
The Tabletop RPGShadowrun supplement "Neo-Anarchists' Guide to Real Life'' mentioned how exciting it was to watch a DocWagon Crisis Response Team respond to a crisis "Code Blue" alert.
The underground WWII Cabinet War Rooms in London did this trope with classic British understatement. Their air raid alarm was a modest doorbell at the exit stairs, with the sign "This bell ringing indicates immediate danger overhead". Bunker occupants were thus warned that going outside was temporarily inadvisable.
A variation on this trope occurs in hospital emergency departments, in which an ambulance crew can radio a hospital dispatcher for "medical control" - asking a hospital-based doctor for instructions on how to manage a critically ill/injured patient while en route. The dispatcher's radio will emit a loud, harsh buzz/honk sound, audible throughout the triage area, when such a call is placed. If the call warrants assembling a resuscitation team, the dispatcher will then issue an overhead page to the rest of the department, indicating what the emergency is (adult or pediatric, medical or trauma) and how long before it arrives.
It is also worth note that most hospitals DO have a "code red." It is used in case of fire. (other common codes are blue, in case of cardiac arrest; ADAM, in case of missing persons; triage, in case of a large amount of incoming emergency patients; and some sort of bomb threat code.)
This is also how most fire departments work. Tones will come over the PA system followed by the dispatcher saying which units are to be dispatched and the nature and location of the call.
The tones have another purpose besides an audible alert. Each department in an area will have distinct two-tone alerts that are used to un-squelch pagers and radios, so as to not hear the radio all day unless a call comes in. Firefighters and EMS workers can tell who is being dispatched just by recognizing the tones.
Fire stations in countries where the fire department and ambulance service are separate organisations usually use a simple bell or klaxon to summon the crews to their vehicle or vehicles. British fire stations usually send details about the call-out to an old school dot-matrix printer loaded with carbon paper; ambulances, which are usually off-station to shorten response times and are sometimes called upon to transfer patients between hospitals, have police-style radio sets instead.
Scramble Run Examples:
In the Star Wars Expanded Universe novel Specter of the Past, we are treated to two separate chapters starting with the battle alarm going off at an unfair moment for Wedge Antilles: the first time in the middle of dessert, the second in the middle of the night. (His commander was feeling hunchy, though, and so Rogue Squadron were already sleeping in their ships...)
Moonbase called them too. SHADO Control once called a "Maximum Security Alert - Condition Red".
Wing Commander often featured this, some times called Battle Stations but with the same concept. In particular, the Fighter Launching Sequence in the first Wing Commander game is accompanied by a Red Alert complete with klaxon, even for routine patrol missions.
Video GameStarlancer has a short cutscene of fighter crews running along the corridor while a red light flashes. One can only assume the Squadron Leader's briefings have a tendency to overrun.
Benjamin Glee thinks strafing is the best way to show you're focused, even if there isn't a Red Alert.
Air Force Blues had Barbie eating a sandwich when the the red light came on, followed by his squadron commander yelling at him to SCRAMBLE!
SWAT Kats has their scramble alarm linked to Callie Briggs' communicator. It sounds the alert buzzer and flashes the red light throughout the main building in the salvage yard, especially in the garage where they often are fixing cars. Whenever it goes off, it's time to move move move!
Most uses of this trope can be traced to the real-life Battle of Britain, the first time that radar technology allowed defending fighters enough warning to wait on the ground rather than running constant standing patrols. The 1969 film features many examples, with pilots lounging in the sun in full flight gear until the dispatcher rings the scramble bell.
This practice still goes on today in NATO, where it's called Quick Reaction Alert or QRA for short. The British used it for their V-bombers (which were bombed up), where you possibly had as little as five minutes before nukes started landing, the instruction being take off and head for the "start line" .
The far more common version of this, on a nearly daily basis during the Cold War and about monthly now involves fighter jets (usually two) being scrambled to intercept and escort away Soviet/Russian "Bear" bombers who have entered NATO-monitored airspace to test reaction times- i.e. for the fun of it.
In modern times, many military installations will have a public address system that is used to warn of imminent attack or natural disaster, in a Real Life version of Canned Orders Over Loudspeaker. For the alarms related to enemy attacks, the American military uses a color-coded alarm system, with Red typically being reserved for imminent or ongoing large-scale attacks.
The tradition dates back to World War II, during which the radio broadcast "Condition Red" was used to warn anyone with a radio that the sender had detected an imminent enemy attack, usually but not always by enemy aircraft. "Very Red" was also used a couple of times in the Pacific to describe very large attacks.