Most effective: Large, flat areas like the arms and legs. Least effective: Curved areas which include the underarms, and probably do cause significant trauma to your face as well as other thin skinned areas. Tip #1. Use the blow dryer properly. https://wingrotate9.bloggersdelight.dk/2024/08/23/hair-loss-causes-5-specific-types-of-hair-loss-uncovered/