A man went to see his doctor because he was suffering from a miserable
cold. His doctor prescribed some pills, but they didn't help.

On his next visit the doctor gave him a shot, but that didn't do any good.

On his third visit the doctor told the man to go home and take a hot
bath. As soon as he was finished bathing he was to throw open all the
windows and stand in the draft.

"But doc," protested the patient, "if I do that, I'll get pneumonia."

"I know," said his physician. "I can cure pneumonia."