Although July and August tend to be the warmest months of the year, the months leading up to summer as well as the months just following summer can also be quite warm or even very hot. In this article, the authors share some important information to help prepare physical educators for overseeing activities in the heat and, just as importantly, to prepare their students, the parents, and school administrators. A child's ability to regulate core body temperature in the heat is influenced by a number of factors, including the environment, intensity and duration of physical activity, hydration status, cardio-respiratory fitness, body composition, health status, current use of medications, and clothing, uniforms, or protective equipment. Keep in mind that students can still overheat while exercising in the heat, even if they are well hydrated and fit.