thermoacoustic refrigerator

not to be confused with thermoelectric (direct electricity-to-heat/cool).

These are not toys:  http://qdrive.com/UI/ProductsListing.aspx?mcid=111&pcid=111&ccid=111 shows cryogenic coolers that go down to 50K (yep degrees Kelvin, that's 50 degrees above absolute zero)!.

In particular, in space where there is no air to carry away excess heat, these coolers can regulate temperature of components.

Of course the reverse physics can use a temperature differential to generate a (very loud) sound.

Then refrigeration that does not need electricity, stored fuel, just a campfire: