As the Coachella Valley settles into triple degree temperatures, most desert dwellers know it's time to hunker down in the air conditioning. But that's tough if you have little kids who have a ton of energy to burn. Now, a local company is making it easier for kids to beat the heat. Koolfog, located in Thousand Palms, has donated a misting system to the Children's Discovery Museum of the Desert in Rancho Mirage, and staff say it is making summer…