It is extremely important to exercise with caution during summer days with record heat. Most experts agree that an indoor workout is best when the temperatures rises above 90 degrees but if you still would like to go outside, the best advice is to avoid peak temperatures and make sure that you are sufficiently hydrated. Almost all experts recommend working out first thing in the morning before the temperatures rise. And there are certain other benefits to an early morning workout. Exercising in the morning on an empty stomach is the best way to burn stored fat, making it ideal for weight loss. Research also suggests that morning exercisers may have less of an appetite throughout the day, which could also help protect them from putting on pounds.