A man was on holiday in the Caribbean and, liking the warm tropical weather, settled down for a day's sunbathing. He fell asleep, and after a whole day his legs became sunburned beyond belief. He could hardly stand the pain. He decided to go to the doctor for treatment.

The doctor looked at his lobster-coloured legs and shook his head. "You must realize that this is only a small village medical facility," he explained. "I've really got nothing at all to help you. However, try taking this just before bedtime..."

The doctor gave him one tablet of Viagra. Puzzled, the man asked, "I've got acute sunburn: what's a Viagra tablet going to do?"

"Not a thing for the sunburn," the doctor replied, "but it might keep the sheets off your legs!"