 It's not heat. Heat doesn't kill them. If it gets really hot, like you walk outside and it's like, ugh, one of those days, 90% humidity, it's just 100 and some degrees, what do you do? You run to your car, you turn on the what? The air conditioning. You go to your house, you turn on the air conditioning. You put a fan on, whatever. When bed bugs get that hot, they go, I'm out of here, and they hide. It's not heat. It's thermal.