Tempted to crank up the air-conditioning at the studio when the temperature soars? You may want to re-think your training plans. Working out in the summer heat can lead to quick improvements in fitness. This process, known scientifically as heat adaptation, can be applied to any workout format. Turn up the intensity of your summer training to maximize the benefits of soaring temperatures this summer. Here’s what you stand to gain when you add heat to your summer workouts…and what you need to know to do so safely.