So being an idiot an all, i decided how cool it would be if we could use the evaporation of water to allow people to expend calories, much like exercising, but not.

The heat of vaporization of water is 539 calories per gram. per kilogram of water that is 539 kilocalories or Calories.

the specific heat of water is 1 calorie/gram/deg C. and of vapor .48 cal/gm/C. and if we take body temp as 37 deg C then.

.52*63= 32.76 calories/gm= 32.76 Calories/kg + 539 Calories/kg

this means if we can use our bodies to evaporate 1kg of water we burn 571.76 Calories.

Imagine an apparatus that put very thin layers of water on your body to expend energy in this way.

haha i wonder how long it would take for a kg of water to evaporate(1 Liter).

it's essentially like sweating but not drying it off your body.