Many years ago, I worked at a youth hostel in Tel Aviv, Israel. The owners of the hostel, being Israeli men, were drafted into the army every year. Obviously, when there was a war, they would have to go and fight.
Both of these men hated the army, and had developed several ways to avoid serving. The most memorable was the following: shortly before taking an army phyical exam, they would smoke a cigarette and knock the ashes into a cup of black coffee. When they drank the coffee (they said) their body temperature would rise so that they would appear to have a fever. This would give them a week or ten days until they had to go back for another physical, in which time they would usually find a way to get out of the country until things calmed down.
My question is: would this really work to raise your core temperature, and if so, how?