This warm weather has caused me to have a couple of sleep-deprived nights, so I was wondering what is the longest anyone has ever gone without sleep? asks Wendy Jones, from Erith.

Simon says ... Well, I stayed up all night long to try and find the correct answer to this one, and I hope I've got it right.

This is not an easy question to answer because a lot of long periods of sleep deprivation have probably not been recorded, plus there are some very wild claims on the internet.

A couple of sites tried to claim the record for the longest spell without sleep is 18 days. This seems a little unbelievable to be true.

The answer which seems most reliable and which occurs most frequently is 11 days, or more precisely 265 hours and 12 minutes.

This was apparently achieved by 17-year-old San Diego high school student Randy Gardner in 1964 or 1965, depending where you look.

Reports say Gardner staved off sleep with cold showers and loud music.

His amazing feat landed him a place in the Guinness Book of Records.

Another notorious case of sleep deprivation is disc jockey Peter Tripp who in 1959 stayed up for more than eight days as a promotional stunt.

After a few days, he began to hallucinate, seeing kittens, mice, and cobwebs. He also became paranoid, insisting a hot electrode had been dropped into his shoe.

Sleep experts now believe that long sleepless stints can be dangerous, so attempting to break the record is probably not a wise thing to try.

Well, I hope this fully answers the question, and I hope I haven't put anyone to sleep!

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