Staying hydrated in hot weather can help reduce the risk of heat-related illness. Keep water or sports drinks (with electrolytes) on hand to maintain hydration, and try to stay in a shady or air-conditioned location during the hottest parts of the afternoon.
Mild symptoms -- heat exhaustion -- may include feeling thirsty, fatigue and cramps (legs or abdominal). If left untreated, heat exhaustion can progress to heatstroke.
Heatstroke is serious. Symptoms may include any of the following: dizziness, trouble breathing, headaches, rapid heartbeat, nausea, vomiting, confusion and changes in blood pressure. Skin may be flushed and feel hot and dry (not sweaty). Body temperature may rise to 104 degrees F or higher, and as it becomes more severe, the risk of organ damage (to the liver, kidneys and brain) increases.
Kids are more susceptible to heat illnesses than adults are because their central nervous system is not yet fully developed. Strenuous activity and dehydration make it difficult for young bodies to regulate changes in body temperature, and chronic health conditions such as diabetes or cardiovascular disease and medicines such as antihistamines also increase the risk. Kids are also at risk for heat illnesses if left in a hot car -- even if the windows are cracked and even if it's only for a few minutes. Never leave a child unattended in a car.