When you bring the anatomy into the equation, it becomes apparent that these types of units can actually strengthen your immune system. In layman’s terms, sick and diseased cells in your body have a lower tolerance to heat. When your body temperature increases, these cells can be killed off. As your body temperature will increase while sitting in 140-degree heat, this can kill off those diseased cells. In addition, the excess body heat can also trigger white blood cells and NK cells. These can, in turn, seek out bacteria and destroy them.