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."