Approximately half of the homes in the UK do not have a tumble dryer. My flat is lucky enough to have a 2-in-1 that washes poorly and dries worse, so we mostly hang wet clothes from a drying rack in the living room (it’s also too small to afford us a more convenient drying location that the middle of our living space, but I digress). Because we also don’t turn the heat on very often, I’m often faced with trying to decipher if a hanging shirt is wet or cold or both. Why is it so difficult?
Humans don’t actually have receptors to sense wetness (hygroreceptors) in the same way we have dedicated receptors for things like heat (thermoreceptors) or touch (mechanoreceptors). Instead, when we feel that something is wet, it’s the result of several other sensations being interpreted by our brains, and matched against our previous experiences as wet.
In his famous experiment, published in The American Journal of Psychology in 1900, I. Madison Bentley blindfolded volunteers and dipped their sheath-covered finger into warm, lukewarm or cold water. No water touched the participants’ skin, yet they all clearly felt the sensation of wet. Bentley noticed that the perception was strongest with cold water.
Over a century later, we’ve sussed out that humans’ sensation of wetness is dependent on complex multisensory inputs. Some are tactile, like how we could tell a wet towel from a dry one just by touch. Or how it feels to have your hand underwater, with a slight pressure pushing on the limb from all sides.
Temperature plays a very important role in our perception of wetness. When water evaporates from our skin, the surface drops slightly in temperature. This mechanism is what makes sweating an effective method of cooling down. But it’s also been suggested as part of humans’ liability to confuse the sensations of wet and cold. In experiments, cold but dry stimuli designed to reproduce how quickly skin cools when wet, were perceived by blindfolded participants as wet - “supporting the hypothesis for which as humans we associate certain levels of skin cooling and cold sensation to the perception of wetness”.
Interestingly enough, our perception of wetness is actually a learnt ability, rather than something we’re born with!
With all that in mind, what should we do about the whole wet and/or cold laundry situation?
You’ll want to use your face to feel the potentially wet laundry. More of our warm sensitive thermoreceptors are found centrally, with regions like our forehead and cheeks being more sensitive to warmth than our torso.
And because humans are far less likely to confuse warm and wet for warm and dry, try warming the shirt you’re trying to wear up a bit. Sometimes I’ll heat one edge with a hairdryer. Sometimes I’ll put it on, only to realize it really was wet when my body heats it up a bit.
