[[caption-width-right:259:[[{{Pun}} Too hot to handle]].]]
A hot blade is an edged weapon that somehow heats up, adding the thermal energy of its temperature to the kinetic energy of its blow to achieve AbsurdCuttingPower. When active, it will usually glow visibly (without losing any of its structural integrity, [[MST3kMantra somehow]] [[labelnote:explanation]]Steel-based blades will have any heat treatment ''ruined'' after exposure to such heated-blade usage. You could use some kind of material that can withstand the temperatures the intended heat blade will reach, such as a tungsten alloy or ceramic, but there will be tradeoffs based on the strengths and weaknesses of the chosen material.[[/labelnote]]) because PowerGlows.

Compare {{Vibroweapon}}, which uses extremely rapid vibrations instead of heat to enhance its cutting power. A more advanced weapon is the LaserBlade, where the blade is ''made'' of PureEnergy instead of just adding (heat) energy to a physical blade. Hot blades are more common in a ScienceFiction setting. Its more {{fantasy}}-oriented counterpart is the FlamingSword; a hot blade retains a touch of PlayingWithFire while requiring less WillingSuspensionOfDisbelief.

Usually used with [[SwordTropes swords]], but other bladed weapons are also seen occasionally. A subtrope of AbsurdCuttingPower. Unrelated to the idiom "like a hot knife through butter"... though hot blades may, indeed, cut through things in such a manner.



[[folder: Anime and manga ]]

* In the ''Franchise/{{Gundam}}'' franchise, the next step down from EnergyWeapons like beam sabers is heat weapons, the most iconic of which is the [[Anime/MobileSuitGundam Zaku II's]] heat hawk. Another well-known example is [[Anime/MobileSuitGundamWing Gundam Sandrock's]] heat shotels, which become [[{{BFS}} ludicrously huge]] in ''[[TheMovie Endless Waltz]]''.
** At one point in [[Anime/MobileSuitGundam the original series]], a heat hawk is able to briefly parry the Gundam's [[LaserBlade beam saber]], which is formed from superheated plasma. You think its [[FridgeBrilliance because a heat hawk blade would by necessity have a higher melting point than the Zaku's armor]] before you know that the AllThereInTheManual tells you the blade of the heat weapon is actually plasmarized and maintained its form (thus they are just lesser example of beam weapons with lower tech).
* In the battle at the sea in ''{{Manga/Berserk}}'', Schierke's fire magic was used to turn Guts' [[{{BFS}} Dragonslayer]] into one of these.
* ''Manga/{{Bleach}}''
** FillerVillain Shusuke Amagai's Zankpaktou has this when its hilt [[FlamingSword spouts flame]].
** Captain Yamamoto's Bankai Seems to be this, along with a fullbody flame armor. Both of which are ''as hot as the sun''.
* In ''Manga/OnePiece'' [[ShockAndAwe Enel]] does a variation by using his electric powers to turn his trident into molten metal in order to burn [[RubberMan Luffy]], who's immune to direct attack by Enel's lightning.
** There's also Shura from the same arc who uses a Heat Javelin, a JoustingLance with a Heat Dial inside it that lets him stab and burn things simultaneously.
* ''Manga/{{Yaiba}}'' has Gold, who can apparently heat up his gargantuan SinisterScimitar somehow. However he does this once.
* In ''{{Anime/Kuromukuro}}'', [[FishOutOfTemporalWater Kennosuke,]] a samurai from the SengokuJidai, has a laser-edged katana that he took from an [[AncientAliens ogre.]] Recreated (sans laser) by [[https://www.youtube.com/watch?v=Q598DP27tGA Man At Arms]].


[[folder:Comic Books]]
* In Comicbook/{{Supergirl}} story ''Comicbook/DemonSpawn'', the titular heroine faces up to Nightflame, a villain that can heat up her huge magic sword.
* In ''Comicbook/SupermanVsTheAmazingSpiderMan'', Comicbook/LexLuthor forges a sword imbued with superheated red sunlight that can hurt Franchise/{{Superman}}.
* Thermal swords, which presumably were super-heated based on the name, were the favored melee weapons of the Dinobots in Marvel's run of ''Franchise/TheTransformers'' G1 comics incarnation.

[[folder: Fan Works ]]

* ''Roleplay/CityOfChains'' has ''Everburn,'' Lucien's two-handed [[{{BFS}} sword]]. Despite the name, it is this and not a FlamingSword.
* ''FanFic/Tech10Rebooted'' has the Pyronaut Blade, an alien weapon that can pierce through most armor when at full temperature.
* ''FanFic/XCOMRWBYWithin'' has Blake carrying a knife with a low-power laser in the handle, which heats the blade and allows it to more effectively penetrate armor and hardened skin. [[note]] Blake is the only one stated to have one, since XCOM operatives, with the exception of [[HollywoodCyborg MEC]] [[RocketPoweredWeapon Troopers]], do not carry melee weapons. She specifically asked [[TheEngineer Dr.Shen]] if he could make something for her to use as a last resort.[[/note]]


[[folder: Film ]]

* Optimus Prime from the ''Film/{{Transformers}}'' movies uses some of these to cut Decepticon's heads clean off.
* In ''Film/PiratesOfTheCaribbeanTheCurseOfTheBlackPearl'', after Will [[ThrowingYourSwordAlwaysWorks uses his sword]] to jam the door of the smithy and cut off Jack's escape route, he grabs a replacement out of the forge. It looks impressively glowy but doesn't last very long; fortunately there are plenty more on the racks.
* ''Film/TheHitchhikersGuideToTheGalaxy'' has a throwaway gag about a knife that toasts bread while slicing it.
* In ''Film/TheWolverine'' The Silver Samurai was able to cut Wolverine's admantium-coated claws with a superheated Adamantium sword. Since Adamantium suffers from a LikeCannotCutLike rule, presumably the intense heat melts the claws off.


[[folder: Literature ]]

* The Warpsword of Khaine from ''Literature/MalusDarkblade'' is said to feel like it just came out of the forge, and it burns whatever it hits.
* In ''Literature/CodexAlera'' many of the High Lords firecraft their swords, because a bleeding wound can be watercrafted better easily enough, but a cauterized wound is unhealable. Since this causes their swords to shine brightly, they also use them to send signals and challenges that can be seen across the chaos of a battle.
* In Clay and Susan Griffith's Vampire Empire series, it is TwentyMinutesInTheFuture and remnants of a steampunk British Empire barely escaped a vampire apocalypse. Among the weapons used by humans against the vampires is the Fahrenheit Blade. These are blade weapons, including khukris, that have a special sheathe which will coat the steel blade in volatile chemicals. This heats the blade to extremely high temperatures and are more devastating against the heat-sensitive vampires than regular swords.


[[folder: Live-Action Television ]]

* In ''Series/{{Supergirl 2015}}'', Vartox wields a red hot axe that can cut a Kryptonian. Ironically, Supergirl destroys it by blasting it with heat vision until it can't take the strain and explodes.


[[folder: Tabletop Games ]]

* Many Warhammer swords (at least in the way they are visually depicted), both ''TabletopGame/WarhammerFantasy'' (Archaon) and ''TabletopGame/{{Warhammer 40000}}'' ('''THE GOD-EMPEROR OF MANKIND'''), even when some flames might flicker depending on the artist, verging into FlamingSword territory.
* ''TabletopGame/MutantChronicles.''
* ''TabletopGame/CallOfCthulhu'' supplement Cthulhu Companion, adventure "Valley of the Four Shrines". The East shrine is dedicated to Cthugha, a deity made of fire. A sword found in a secret room can be made to glow yellow-hot, which will do damage to creatures vulnerable to fire.
* ''TabletopGame/{{Exalted}}'': A Malfeas charm turns a blade too burning hot ''[[InvertedTrope to be wielded]]'', forcing your enemy to either drop it or suffer lethal damage. Another version of this charm targets armor instead... and it's not easy taking off your armor during a (heh) heated battle.
* And of course ''TabletopGame/DungeonsAndDragons'' is full of these. As well as (among others) [[ShockAndAwe lightning]] and [[AnIcePerson cold]] versions. Not restricted to bladed weapons, though...
* ''1001 Science Fiction Weapons'' for D20, by Plain Brown Wrapper Games, also has a section on superheated blades. Various blades are used, including a [[SinisterScythe scythe]]; though unlike the supercooled weapons available in the book, the superheated scythe is not useful for non-combat reaping of wheat as the crop is set on fire. It is stated that if you see one of these hanging on the wall, you're probably dealing with a villain.
* In ''Obsidian - Age of Judgement'' from Apophis Consortium, one of the expansion books has a gun version of this trope. Normally flamethrowers are the weapons of choice against the undead, unfortunately they come in only one size and don't do that much damage compared to the larger machine guns. So a new weapon was invented, it's a gun with a mechanism that separates the bullet from the casing. It then superheats the bullet until it's almost molten and then the casing with charge is fired. So the super-hot bullet is shot out at high velocity and will rip up standard targets, while also incinerating enemies that are bullet-resistant.


[[folder: Video Games ]]

* The Cosmic Knifes from the Dead Money expansion of ''VideoGame/FalloutNewVegas'' can be made into this. It's an indestructible AbsurdlySharpBlade that has been heated with a heating pad and apparently retains its heat for a ridiculous amount of time, giving it even more destroying power while still allowing the handle to be cool to the touch. It has an x5% critical hit chance multiplier and set foes on fire. However it still is covered with Cloud residue, leaving it more brittle than cleaning it with Abraxo-brand cleaning agent.
** There is also the Saturnite Fist in ''Old World Blues'' dlc. Just give it to the crazy toaster in Big MT and it will become the Saturnite Fist Superheated which glows red hot and sets enemies on fire. A wonder how you [[ConvectionSchmonvection don't burn your own hand]] while wearing it.
* One of the bosses from ''VideoGame/ChronoCross'' uses a {{Steampunk}} version (a NighInvulnerable, HumongousMecha), but this is technically a fantasy setting.
* The (in)famous Pyrotechnic Axes in ''VideoGame/ArcanumOfSteamworksAndMagickObscura'' presumably work this way. They're one of the strongest weapons in the game, assuming you're a melee-based technologist.
* VideoGame/{{Strider}} Hiryu's Cypher uses plasma to achieve this effect.
* Nero's Red Queen from ''VideoGame/DevilMayCry 4'' has a special mechanism inside it; the sword has a gasoline fuel inside, and the sword can be revved; when doing so, it sprays out the fuel to the blade as well as igniting it, making the blade glow hot red.
* Though they are not technically swords, the hooks thrown by Spider Splicers in the ''VideoGame/BioShock'' games are glowing red hot. They are probably heated by plasmid use on the part of the splicers.
* The Thermic Lances in ''VideoGame/XComTerrorFromTheDeep'' are a combination of Hot Blade and {{Vibroweapon}}, and are pretty effective against the [[DemonicSpiders Demonic Crabs]]. [[note]]Ok, they are actually lobsters.[[/note]]
** The final upgraded blades for the Rangers in ''VideoGame/XCOM2'' are hot enough to set enemies alight sometimes.
* The [[http://masseffect.wikia.com/wiki/Omni-blade#Omni-Tool_Weapons Omni-blade]] in ''VideoGame/MassEffect3'', the hologram is so the user doesn't accidentally burn themself.
* In ''VideoGame/MetalGearRisingRevengeance'', LQ-84-series [=UGs=] can throw superheated knives that are able to penetrate (and partially melt) stone and metal. Perhaps notably, Sam's sword also has a distinct red blade but ''isn't'' a HotBlade; just an exceptional VibroWeapon. Sundowner's weapon also seems to count, as visible heat and steam can be seen as he slowly slices across the President's neck in the intro
* A variation from ''VideoGame/HalfLife2'': an [[AutomaticCrossbows electromechanical crossbow]] that launches red-hot ''rebar rods''.
* ''VideoGame/{{Warframe}}'' has the Heat Sword, Heat Dagger, and Dual Heat Sword (sword+dagger combo), which do fire damage on some of their special attacks. All of them have visibly red-orange blades with glowing segments. Grineer melee weapons like the Cleaver, Machete and Sheev also have red-hot powered blades.
* In ''VideoGame/SuperRobotWarsCompact2'', the Alt Eisen carries a "Heat Horn" mounted on its head and functions like the Heat Hawk of the Zaku II. When it's [[MidSeasonUpgrade rebuilt and upgraded]] into the Alt Eisen Riese, the weapon is turned into the "Plasma Horn", with an additional feature of ShockAndAwe.
* [[VideoGame/GuiltyGear Sol Badguy's]] Fireseal(and it's upgrade, Junkyard Dog) allows him to channel his flame powers better. It also allows him to cut with it, despite the blade part being a blunt rectangle.
* [[VideoGame/RocketKnightAdventures Sparkster the Rocket Knight]] sheathes his sword ''in'' his jetpack, and several of his stronger attacks have his sword glowing with a blue, orange, or red flare indicating that he traps the heat in his sword. One of the powerups he can find in ''RKA 2'' upgrades him outright to a FlamingSword.
* In ''VideoGame/YandereSimulator'', Yandere-chan has the option to heat up a knife blade with blowtorches. As of right now the effect is more cosmetic than of practical use...unless you want to turn it into a FlamingSword instead.

[[folder: Western Animation ]]

* WesternAnimation/{{SheZow}}'s EvilTwin [=SheZap=] has a curling iron that combines this with LaserBlade.


[[folder: Real life ]]

* [[http://www.webcitation.org/query?url=http://tribune.com.pk/story/219719/excorcism-16-year-old-tortured-with-hot-knives/&date=2011-07-29 Sufi tortures a 16-year-old boy with hot knives in order to "exorcise" him]].
* Heated blades have been used for [[HealItWithFire crude amputations to cauterize and disinfect the wound]].
* In real life, this is AwesomeButImpractical. As any blacksmith or metalworker can attest, steel loses its hardness the closer it gets to its melting point.
** [[https://www.crucible.com/eselector/general/generalpart4.html Special metallurgy that can mitigate this has existed since the 1930s or so]] with "high speed steels" - which were developed in response to modern industrialized machinery (like drills, end mills, ect.) becoming more capable and having higher RPMs. So, instead of finding roundabout solutions to the problem of drill bits heating up and dulling because of it, high speed steels were developed which simply retain their regular hardness at high temperatures with addition of molybdenum, tungsten and cobalt. With some of these steel alloys, ''operating'' temperatures in excess of 500°C (almost a thousand degrees Fahrenheit) are possible. More if you're willing to sacrifice some hardness. To make things even better for potential application of this, high-speed steels are popular in high-end cutlery and knife making. Steels like CPM M4 are becoming extremely popular because of how "hard" the steel can be ran (usually well above 60 HRC, which is about where most steels start to top out at before becoming too brittle - some alloys can almost reach 70 HRC, which is nearly on par with the higher end of ZDP-189) and it's wear resistance. Steels like CPM M4 and CPM Rex T15, especially, on a properly forged knife would seem like space voodoo magic to someone unaware that such capabilities were possible. Heating one up, however dangerous and unwise that would be to use, is certainly possible.
*** However, [[https://www.youtube.com/watch?v=hjSheQ7LgJ4 As this experiment tells]], while a RealLife HotBlade may ''look'' impressive in some stunt, cutting power is not much increased, even with incandescent 1000°F knife.
*** Good luck trying to push-cut through a 20oz plastic soda bottle (with the cap still on, no less) with an ordinary kitchen knife that isn't heated enough to weaken the plastic you're push-cutting into... Or without using hundreds of pounds of force behind the cutting edge (which, while the person in the video was pushing with enough effort to cause straining, if the same blade in question was NOT heated they would not be doing much or any cutting at all like what you see here). It's not so much increasing the cutting power as it is making what your cutting easier to cut into... because it's melting.
* There once was a practice called "Blood Tempering," in which a red-hot blade is inserted by stab-wound and/or anally into a slave or prisoner of war, as it would cool the sword at body-temperature. This supposedly made the blades much stronger, and always killed the stab victim in practice. "There was once" is the phrase because no one does it anymore and even in the past it was uncommon. This is because the human body has such a wide variety of liquids and materials, it invariably created a blade with a poor, uneven temper that shattered easily. It was rarely maintained for any length of time in any culture, despite a moderately common myth.
* Hot knives can be used to smoke drugs (generally cannabis, but sometimes also the more pastelike smokable opiates) in a process called "[[https://en.wikipedia.org/wiki/Spots_(cannabis) spotting]]." The tips of two knives are heated, and a small quantity of the marijuana (or what have you) is first rolled into a little ball and then pressed between the knife tips. This creates a massive quantity of smoke, which is then inhaled (possibly through a funnel called a spottle).