While frostbite, caused by prolonged exposure to the cold, might kill some tissue, the real danger is hypothermia, Scofield said. When the core body temperature falls around to 68 degrees, the heart might stop. And at 63 degrees, the brain stops functioning. No wonder Santa is always on the move and dressed so warmly.
If children really wanted to give Santa an exotic treat, they might want to leave him some fruits and vegetables. Because as harsh at the cold of the Arctic is to people, it's even more inhospitable to most plant life, which means a ripe orange or a bunch of celery might be just what Old Saint Nick really needs.
Another reason to leave Santa a basket of oranges is to help him ward off illnesses. It's not just difficult for big animals to live at the North Pole; microscopic germs and bacteria also have trouble surviving the cold, Scofield said. Which isn't to say there aren't a few, but bacteria — like humans — tend to congregate where the living is easier.
So when Santa visited all those houses on Christmas Eve, he had to watch out for the flu and colds that are going around.
Even though they might not survive the climate out on the ice, germs and bacteria can flourish inside the body, he said.
“Luckily for Santa, even if he does catch a cold, he'll have plenty of time to recover before he starts work again next year,” Scofield said.
Greg Elwell is a public affairs specialist with Oklahoma Medical Research Foundation.