Imagine a personal heating system that works indoors as well as outdoors, can be taken anywhere, requires little energy, and is independent of any infrastructure. It exists – and is hundreds of years old.
  • poVoq
    3•2 years ago

    True, but a single use chemical reaction might produce heat more efficiently than the stove used to heat the water.

    Reusable chemical heat pads that depend on heat stored in an aggregate change from liquid to solid also store more heat per volume than water I think.