The temperature at which as soon as you leave an air conditioned area and enter the outdoors, you immediately start sweating (often profusely).
A condition (often experienced in Florida) where as soon as you step outside, there is condensation under your pits.
A couple walking from their house to the car.
Husband: "Oh my god, it is soo hot out here!"
Wife: "Oh, I know! I can already feel the imedisweat forming under my right armpit and we just stepped outside..."