So the brain receives confusing signals. It’s not sure if you’re just being exposed to moderate warmth or being burned. So to be safe the nervous system responds to the more severe stimulus: pain. The brain tells the body to react the same as if it’s being subjected to a burn, that is, pain, sweating, and flushing. You respond to the brain’s message by gulping a cool drink to quench the perceived burn. Of course, we humans are a strange breed. We have taken a response that normally signals danger and made it pleasurable. I guess that’s no surprise, since we are also the species that bungee jumps and sky dives.