After his examination, the doctor asked the elderly man, "You appear to be in good health. Do you have any medical concerns you would like to ask me about?"
"In fact, I do", said the old man, "After I have sex with my wife the first time, I am usually cold and chilly. Then, after I have sex with her the second time, I am usually hot and sweaty."
Later, after examining his elderly wife, the doctor said: "Everything appears to be fine. Do you have any medical concerns that you would like to discuss with me?"
She replied that she had no questions or concerns.
The doctor then said to her, "Your husband had an unusual concern. He claims that he is usually cold and chilly after having sex with you the first time, and then hot and sweaty after the second time. Do you have any idea why this may be?"
"Oh, that silly old fart", she replied. "That's because the first time is usually in January and the second time is in August."