Myth: 

The more you sweat, the more fat you lose.

If you exercise in extreme heat, or wear one of those shiny rubber-like suits, you will absolutely sweat. And you will absolutely lose weight. 

However ... this weight decrease is due to water lost via perspiration, not from fat loss. 

And would you like to guess what happens once you consume food and water? Bingo. The weight comes right back.

More importantly, you put yourself at risk for heat injury by undertaking such an extreme method. Heat injury can, in some cases, be fatal.

Keep in mind that sweat is an indication of  factors such as temperature, humidity, body composition, and your physical condition.

It is not an indicator of the amount of energy you are burning — or, more precisely, the amount of fat..