It’s summer in the Northern Hemisphere – and hot, really hot, in many areas. We are warm-blooded. Our bodies produce heat. When a muscle contracts, only about 25 percent of the energy is used for the muscle work. A surprising 75 percent of the energy is turned into heat to keep our temperature up. If we didn’t have a way to get rid of extra body heat, our temperatures would keep on climbing. Strenuous exercise would raise the body temperature by about 2 degrees every five minutes, reaching fatal levels in only about 20 minutes. We get rid of extra heat by radiating it to the cooler surrounding environment, by evaporating extra fluid, and by letting air currents carry it away through convection. If the surrounding air temperature is hot, if the air is not moving, and if the person is getting dehydrated, heat becomes dangerous. Whether it’s a baby at the beach on a hot day, a toddler left in a sweltering car, or a budding young athlete at an exhausting practice in the sun, heat injuries are more common than people think and prevention is easier than treatment.