Both people and pets can suffer a heat-related illness. Reduce your risk by wearing lightweight, light-colored clothing. Avoid strenuous activity during the hottest part of the day. Drink plenty of water, regularly. Drinks with caffeine or alcohol are not a substitute for water because they cause the body to lose more water than they contain. Never leave children or pets in vehicles in warm temperatures, even if the windows are open. Make sure pets have plenty of water and areas of shade to which they can retreat.