Losing weight when it's hot out?

I read somewhere that when it's really hot and you don't turn your cooler on very high, your body burns more calories because it's having to work harder to keep your body cool.It also said in the winter if your heat isn't turned up all the way you'll burn more calories because your body has to work harder to keep itself warm. Is this true, and if so, why?
Answer:
Yep. Listen to daddy.

---