I bought the Coleman version of Cold Heat at Frys for $9.95 on sale. I
am keeping it even though it is not as good as a conventional soldering
iron for most work.
For removing small components from circuit boards it works quite well
without damaging nearby pieces with excessive heat. It is just a
resistance heating device which places the 6 volt battery voltage
directly across a conductive shorting piece that is your soldering
target. Crude, but sometimes useful. Another tool for my overcrowded
tool kit.