Answer:
latent heat of vaporization
Step-by-step explanation:
The cooling effect of water comes from it's high latent heat of vaporization. The latent heat of vaporization is the heat required to cause a phase change from liquid to gas especially for water.
Water cools when it evaporates because this phase change process requires that molecules of liquid water are set free as a result of increase in temperature of a body. This will increase the kinetic energy of the molecules and as gas forms, the molecules will be set free. The gas molecules will carry the heat away when they form and thereby leaving the body with a much lower temperature.