Quality breathable running clothing an essential aspect, when running in high temperatures, is the running shirt that we use. Which leads me to my first of 20 tips to make summer running fun. Try running early in the morning. It's the coolest, most serene part of the day, and there's nothing. These essential items will help keep you cool and comfortable while running in the summer. Look for items that are loose and light. Many shirts are now made with special air. These are designed to help keep your body warm in cold temperatures but can be counterproductive when running as logging the miles makes you work up some. Health running belt sport waist pack. Health running belt sport waist pack.