When Luke escaped from the Wampa cave, couldn't he use his lightsaber as a heat source? Maybe not directly but by heating up the ground for example. Near the beginning of episode one it is shown lightsabers can melt metal blast doors, leaving them red hot glowing. I can imagine that if you try to stick a lightsaber in the ground it would also heat up a lot.

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    It would also be smart to stay in the cave instead of going out into the storm. But he was not top performing that time, you know, blunt force trauma and everything.
    – Ghanima
    Nov 29, 2015 at 3:04

1 Answer 1


Basic physics. While sound transmits through vacuum in Lucas Physics, heat transfer appears to work the "normal" way - you can't heat up a random material and have it retain heat indefinitely. It worked very well with a metal door on Trade Federation starship, precisely because metal is an awesome heat conductor.

What Luke had to work with was:

  • Open space

    This means you require a heat source which absorbs a LOT of heat energy and very slowly disgorges it into a large-ish (body sized) area

  • Snow.

    Obviously, heating that with a lightsaber ain't exactly useful. And I suspect melting snow for hot water wouldn't have worked as we know Lightsabers short out in water.

  • Earth

    Totally unsuitable as heat absorber. It's very slow to absorb and transmit heat, so you'd need TONS of time to heat a sufficient area of the ground to keep yourself warm. Heating just the small extra 5" area right around where you stuck the lightsaber into the ground won't help.

  • Organic material (dead bodies of Wampa or Tauntan).

    You can't really heat those either - they are mostly water + carbon, so you'd either get evaporated water that's lost, or char which isn't useful for heating yourself long term.

  • Lightsaber with finite amount of energy in it.

    Meaning, it's quite possible and even likely it would have died well before the night was over.

Now, presumably, as one of the commenters noted, Luke could definitely McGuyver things a wee bit better. MAYBE (remember, he did pretty much do a very optimal survial approach, hiding inside a dead Tauntan's body in the first place):

  • Build a snow Igloo around Tauntan's body, for even better heat isolation/retention

  • Get a large piece of metal, and extremely heat-resestant rock. Melt the metal using the ligtsaber in the rock, and use that as a heater. And pray that the lightsaber wouldn't exaust its energy cell in under an hour.

  • If Luke didn't panic and would have thought things through, he would at least have cut the wampa open and stay in the cave till morning.
    – Ghanima
    Nov 29, 2015 at 3:24
  • @Ghanima - unless I'm mis-remembering, Wampa was already dead and Luke wasn't up to moving it? Nov 29, 2015 at 3:26
  • He kills it (or at least slices its arm off), panics, and runs out into the open. (Might be different in the releases, who knows what George did.) So, at least he could have used the wampa's corpse to the same end like Han with the tauntan...
    – Ghanima
    Nov 29, 2015 at 3:30
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    Also I cannot refrain from refuting your key point here "finite energy". Granted, it's canon that the energy is limited, but... they melt a solid (as in really solid) blast door. Take the heat capacity of a large mass of metal, that's the lower limit of the energy the light saber can provide. And that's for certain enough to heat one human. (This however is where the other parts of your answer come into play, which I cannot object ^^)
    – Ghanima
    Nov 29, 2015 at 3:35
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    @Hatandboots, mixed up as Luke was, he would certainly not want to pass out next to an active light saber ("closer and closer to the blade").
    – Ghanima
    Nov 29, 2015 at 3:55

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