Could Body Heat Power Electronics?

If you use your body heat, then by definition the 'clothing' will cool you, but the purpose of clothing is generally to keep you warm... Reductio ad absurdum.
Ah, but in hot places clothing is only there for protection from the heat! Well in which case use the heat source, (sun) instead.
What if you are somewhere hot but not sunny?
Just go and get a beer and stop trying to do daft things like power stuff from your clothes/body heat.
If you really must have an source of electricity a wind up generator would probably do the job, or a battery.

Del

Gee another source of "free" energy!

Seebeck, Peltier, Thompson...Why not? A demonstration is required.-

Society is increasingly pushing towards technologies that waste less energy.

Thus any place where waste energy exists is a potential source for energy harvesting.

I just downloaded an article about powering mobile equipment using stray environmental radio frequency energy.

So if the body produces waste heat, this is obviously another candidate for energy harvesting technologies. As mentioned, any such device would tend to make one feel cooler, so it seems more practical in warm environments.

That's wooly thinking, the simpler answer is often to prevent the waste rather than trying to capture it.
Del