Former poofy-banged hairspray addict here
Does anyone remember the Genera Hyper-Color shirts?
Believe it or not, I still have mine. In fact, I just discovered it the other day, and it still works!
For those who are unfamiliar, they change color when heat is applied--ie, when you get hot--your armpits would turn, say, a bright neon pink.
Yep--an interesting 80's invention. My shirt was orange and white tie-dye that turned a blotchy neon pink.