Punching in self-defence?

Punching to the head without wraps or gloves isn't recommended because of the chance of injury to the hand and wrist when they connect with the hard surface of the Skull but when you're involved in a dangerous situation out on the street, with the the Adrenaline flowing, you're instincts from training kick in and it feels natural to throw a punch at your attacker. The other night outside McDonalds after being in a nightclub, someone tried to start a fight with a few of my friends, (I was on the phone when it started, but when I came back there was murder lol) thankfully it blew over but when I seen what was happening the adrenaline started flowing and it suddenly felt completely natural to go over and hit the guy with a straight right.:bbb However, I broke my wrist last year and was wary of punching him in case I injured it again. Was just wondering in I am ever forced to use punch someone in Self-Defence what part of the head should I aim for to minimise potential injuries to my hand/wrist, I know for example not to aim for the forehead because its the thickest part of the Skull.

(P.S., I used to do Martial Arts but with Boxing I don't have the time or energy to go back, and because I train so much if I''m ever in another situation like that I'll probably start throwing punches without thinking.)

 

No need for that, Mods, feel free to lock the thread if you think its inappropriate, though I really did mean it as honest question.