When angered, it is human nature to punch toward the head. In boxing, the pubic cheers for head shots and wonders why the fighter that was hitting the opponent in the head lost the fight. Boxers know body shots will win the fight, either by knockout, by weakening the opponent so a head shot may be effective, or by punishing the opponent until he or she quits.
In Taekwondo training and in class sparring sessions, we practice punching to the head. However, is this a prudent thing to do? The head is hard and hands are fragile. This is not a good combination. Bare hand punches are an excellent weapon to use to attack the soft body, but not the hard head. There are soft targets on the head, such as the nose or the jaw hinge, but the targets are small, surrounded by hard bone, constantly moving, and difficult to hit. Since the bones of the head are harder, thicker, and more structurally sound than the bones of the hand, if your punch hits the forehead, areas of the jaw, or the cheekbones you may injure your hand so as not to be able to use it to defend yourself any longer. If you punch someone in the mouth, you may cut you hand on his or her teeth. The Journal of Clinical Infectious Diseases reports a confirmed case of a police officer contracting both HIV and hepatitis C from punching a suspect in the mouth. There is also the possibility of contracting an infection from the bacteria in the opponent's mouth.
If you think you need to strike the head with your hands, the safer and more effective technique is to use the palm heel strike. Palm strikes to the head can be lethal and they protect the fragile bones and joints in the hand. There is an old saying: hard strikes soft, soft strikes hard. Use hard weapons, such as fists, elbows, knees, fingertips, etc., on soft targets, such as muscles, torso, eyes, etc. Use soft weapons, such as palm heel, sole of the foot, etc., on hard targets, such as the head, elbows, knees, and other bony surfaces.
In a self-defense situation, resist the temptation to punch to the head and you will have the use of your hands for a longer period of time during the attack. You will also be able to use your hands in your daily activities the next day.