Seems to me that you’d need some sort of transfer medium (RickJay’s water), if indeed lightsabers do not radiate or emit heat except through contact. So what you could do is use the lightsaber to slowly slice a slab off of a chunk of some kind of metal with really high thermal mass, and use that slab as a broiler, or as a heat source in an oven or something. Or use the lightsaber to boil water.
Otherwise, any sort of food/lightsaber contact is going to result in incinerated food.
Hmm. Lightsaber slow cooker?
I’m seeing a market, here.
The real trick, of course, is shaving with a light sabre. And not just facial hair.
If I could write, I’d write a story about a Jedi unicorn with a light saber for a horn.
Because you can find everything on the Internet: a picture on DeviantArt, of a Jedi unicorn fighting a Sith unicorn.
From Science:
Of course the lightsaber emits heat. It is a very bright lightsource, and light carries heat.(well energy, which just about always expresses as heat)
How much you get might be a problem.
From the movies:
Only by contact!
There are several scenes where lightsaber duellists hold their lightsaber VERY CLOSE to their own face, with no discomfort.
But in contact with flesh it sears instantly (Mos Eisley cantina fight)
and in sustained contact with metal it melts the metal very rapidly
((p.s. From that door-melting scene the apparent power output of a lightsaber is several GIGAwatt of power.
Apparently the Star Wars universe has gooooooood batteries!))
Need answer fast?
I think if it did boil water, it’d boil it to a temperature too hot for the pot to handle. (I am not a scientist.)