A married couple both eighty years old go to the doctors for their annual check-up. They were put in seperate examination rooms.

The doctor enters the room where the husband is waiting and does a check-up and proclaims 'You are extremely healthy for your age, are there any concerns?

' Yes' says the gentleman, 'When I make love to my wife I sometimes get so hot that I turn the air conditioner on. Sometime I get so cold that I have to turn my heater real high.'

Puzzled, the doctor says that he does not have an answer for him and moves on to examine his wife. After performing a full check-up, he finds her as healthy as her husband.

The doctor is totally perplexed by what the husband has told him and decides to ask the wife about it. The doctor asks the wife if she has any ideas why he feels so hot one time and very cold the next time when they are making love.

The wife proclaims to the doctor 'Oh, that old fool, it is because we only make love once in the winter and once in the summer.'