Buzz
As kids head off to summer camp, many of them will continue the age-old ritual of trying to make their friends urinate in their sleep by placing their hand in warm water. But does this actually work, or have countless summer campers wasted their time over the years?
The truth remains unclear. There’s ample anecdotal evidence supporting the idea that this prank works, but as the saying goes, the plural of anecdote is not data. The story of a friend of a friend claiming this happened years ago at camp doesn’t offer solid proof. To investigate further, the MythBusters tested the prank on themselves and a crew member, using sleep-monitoring tech and moisture alarms on the beds. Their results were disappointing: zero wet beds (though with just three participants, the sample size is too small to make conclusions).
If the prank is effective, it likely works due to the power of suggestion. We’ve discussed before how hearing running water can trigger the need to urinate, forming a conditioned reflex because of the connection we make between the sound and the act of urination. Wet hands are often associated with this reflex, as people typically wash their hands after using the bathroom, and it doesn’t appear that people lose control of their bladders when their hands are submerged in warm water otherwise.
There’s a phenomenon known as 'immersion diuresis,' which refers to the need to urinate caused by changes in temperature and pressure when the body is submerged in water—this explains why swimming makes you have to pee. However, studies indicate that this effect requires either the full body or entire limbs to be submerged, meaning that just immersing a single hand isn’t enough to trigger the response.
