After a long day on the slopes, your shins tender and thigh muscles screaming, the ubiquitous ski lodge hot tub next to the hill is something to look forward to. Maybe you’ll meet a sweet ski bunny luxuriating in the tub on the roof, surrounded by snow drifts and other bikini-clad honeys tuckered out from the long day skiing.

Most likely though, the tub will be full of bros downing brews looking for the same slope-side females you were hoping to cozy up next too. And if a sausage party in hot dog water isn’t enough to dissuade you from taking a dip to soothe sore muscles, a new study published in Environmental Science & Technology Letters should sufficiently gross you out.

Turns out that urine in pools and hot tubs isn’t just a skeevy, minor problem. The nitrogenous compounds in pee and sweat (like urea) can react with the chlorine in these man-made water bodies to create other compounds that act like disinfectant. These disinfectant byproducts (DBPs) include trichloramine, which is linked to eye irritation and breathing problems.

So researchers at the University of Alberta in Canada recently developed a rapid test that looks for an artificial sweetener called acesulfame potassium, or ACE, in the pool and hot tub water. The sugar substitute is not destroyed or altered when coursing through our digestive system, meaning if you eat some and then pee it out, it’s going to be fully intact into whatever body of water you let loose in.

To test their new test, they tested 31 active pools and hot tubs in two Canadian cities, along with the tap water used to fill the basins. They found up to 570 times more ACE in the pool and hot tub water than clean tap water, and estimated that over 7 gallons of urine—equivalent to a medium-sized trash can—was in a 110,000-gallon pool, and almost 20 gallons in a large pool filled with 220,000 gallons of water. One hotel hot tub had approximately three times more urine in it than the worst swimming pool tested.

Our advice? If you don’t want to be swimming in traces of pee and the nasty chemicals that can be created from the mix of urine and chlorine, stay out of hotel pools and hot tubs. Stick to those spots that regularly clean their pools and tubs like higher end gyms or local YMCAs, and check with the manager to see what kind of cleaning schedule they're on. And if you manage to find a good spot, we recommend incorporating some of these awesome pool exercises to get fit while wet.

Just, y'know: Shower when you're done, okay?