10 Reasons You Should Use an Infrared Sauna During the Summer Yuck! Voluntarily sitting in a 130-degree sauna while its 90 degrees outside. Why would any sane person do that? Saunas seem like a no-brainer in the cold, dark, and dreary winter months. But once things start to get warmer and everyone is flocking to the nearest pool, remember to add in sauna time. We all know that the more regular a user you are of an infrared sauna the more amazing (downright magical) the effects are. So why does the usage drop? Because people have been misinformed about the use during warmer months (or they can’t stand the thought.