[quote=@whizzball1]
<Snipped quote by Nimda>

yeeeees
I'm considering coming up with a material that would readily absorb body heat below at a certain temperature, but eventually stop doing so until the temperature lowers sufficiently. I don't know enough about materials to form such a thing yet, but I'm going to learn more about it once I solidify the idea more.
[/quote]

It'd probably be very difficult without electronic components.