After an examination, the doctor said to his elderly patient: '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 my wife and I have sex, I'm usually cold and chilly; and then, after I have sex with her the second time, I'm usually hot and sweaty."
When the doctor examined his elderly wife a short time later he said, 'Everything appears to be fine. Are there any medical concerns that you would like to discuss with me?' The lady replied that she had no questions or concerns. The doctor then said to her: 'Your husband mentioned an unusual problem. He claimed that he was 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 about why?' "Oh, that crazy old fool'' she replied. 'That's because the first time is usually in January, and the second time is in August.'