Why do chefs wear a hat?

Isaac wanted to play 'masak masak' today and be the chef.  He took the round plastic bin that we stored the pieces in and put it on his head and said 'Chefs need to wear a hat so that when they bend down to cook their hair won't get burnt by the fire.  They also need gloves so that the fire will not burn their hands'.  Hmmm.. was it not for hygienic reasons?  Wonder who he asked the 'why' question to.