When sweat evaporates off our skin, I’ve been told we cool down because latent heat consumes some of the heat off our bodies. How does that work?

Question

How does the water take heat from the surface of our skin in the process of changing into water vapour? Does the water take heat out of the surrounding air above our skin as it changes also?

In: Physics

Answer 1

Water is made of molecules, and the different molecules all have different energies. Hotter water has molecules which are generally more energetic. This energy allows molecules to escape the liquid water, becoming a gas. However, the force holding them to the liquid is significant, and so they slow down as they escape, cooling them off.

So, the higher-energy water molecules escape the liquid, cooling it off. These molecules then lose energy as they escape the water, becoming a relatively cool gas.