CB radio slang for an illegal amplifier (usally a modified 10/12 meter ham radio amp.) which brings the 4W AM (12W SSB). output to something like 1000 watts or sometimes higher. As a result, the 26.965 to 27.405 MHz band is littered with stations jamming a single channel and not allowing anyone else to use it (AM does not have the "capture effect" that FM does.) because that person is using a "foot warmer" and it congests the frequency so much that it is unusable, and in turn, more people buy "foot warmers" to combat this interferance from distant stations, and thus the cycle continues.

If everyone who used illegal amplifiers was to stop using thier illegal equipment, range and interferance problems would lessen even for those who abandoned thier illegal equipment.
Dude! Hide your foot warmer, here comes uncle charlie!

Roger that, CRYSTAL PALACE BASE CONTROL has a foot warmer.
by IrishRepublicanArmy December 8, 2003
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When you shit in your sock then put it on.
Johnny had cold feet so he made a kentucky foot warmer.
by OhSchist May 21, 2018
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When you shove your entire foot into a woman's vagina.
I gave Stefani an Alaskan foot warmer last night. She won't text me back.
by LameLayne December 28, 2016
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