Where I worked, we had an Environmental Chamber, if you timed it right with the weather and ran it flat out for a few days, you could get it down to -55C and up to +55C, both of which were fairly entertaining, even for short periods.
In Cyprus, I (stupidly) put my hand on the wing of a matt grey Austin 1800 and managed to peel it off just before big damage was done, but it still blistered the whole palm and fingers. The blister popped at the the wrist and for a couple of days, I had the ability to inflate and deflate my hand at will, by blowing and sucking at the vent of the blister.
Solar cigarette lighters were a popular and quite reliable gadget.