If you always wash your underwear in hot temperatures that’s going to wear them out quickly. Moreover, the heating of the water consumes lots of energy. In fact, you can get the same great results at low temperatures. Provided that the underwear are normally soiled, and they are dried in a machine or sunlight after washing, they can still be washed at 30 degrees with perfect results. Also, be sure to allow the underwear to air out when used, so the fabric doesn’t stay moist. That could create an environment for bacteria to grow. If that happens, or if the underwear is slightly more dirty, you should wash them at 40 degrees. If they for example have visible spots of blood or other body fluids, or if used for high-contact sports, we recommend to wash at 60 degrees.