Adventurous sex always sounds so exciting and passionate. Culturally, “spontaneous” and “exciting” have become synonymous with “better,” and no one’s stopping to ask whether the hot tub, the beach, or the back seat of a car is actually a great idea from a health standpoint. A gynecologist is here to ruin the fantasy a little.

Dr. Kath Whitton, a CREI fertility specialist, gynecologist, and obstetrician, says the conversation around sex almost never addresses location, and it should. “We spend a lot of time discussing with whom and how, but where almost never comes up, and it genuinely matters,” she said, speaking with Body+Soul.

The settings that cause the most problems, according to Dr. Whitton, usually involve water, heat, or both—all of which can disrupt the vagina’s naturally acidic environment and increase the risk of bacterial vaginosis, thrush, UTIs, and irritation.

Here’s where she draws the line.

Public Hot Tubs and Spas

Dr. Whitton’s number one concern. Research has found that around 67% of hot tubs and 63% of swimming pools test positive for Pseudomonas aeruginosa at any given time, a bacteria that can cause a pustular skin rash concentrated in the groin and vulvar region. Warm water also breaks down disinfectants faster, meaning contamination levels are higher than most people assume.

Rivers, Lakes, and Estuaries

Unlike pools, natural waterways aren’t treated or disinfected. “What’s in there is completely uncontrolled,” Dr. Whitton says. These environments can carry E. coli, norovirus, and other bacteria from agricultural runoff, animal contamination, and other swimmers. Even swimming in them carries documented infection risk. So, sex is a big no-no. 

Chlorinated Pools

Safer than a lake, but not neutral. Pool water is significantly more alkaline than the vagina’s natural environment, and chlorine is a chemical irritant to vulvar and vaginal tissue. Research published in the Journal of Obstetrics and Gynecology Canada found that women who swam regularly in chlorinated pools had more disrupted vaginal bacteria than those using saltwater or brominated pools.

The Beach

The only sex on the beach worth having comes in a glass with a tiny umbrella. Sand causes physical damage—even fine sand creates tiny abrasions to the sensitive skin of the vulva and perineum, is nearly impossible to fully remove, and makes condom use practically unreliable. “Those small skin breaks make infection easier to establish,” Dr. Whitton says.

Natural Hot Springs

The aesthetic is undeniable, but it’s not a place you want to get frisky. Natural hot springs have uncontrolled pH and mineral content, and can carry bacteria, parasites, and amoebae, and the heat compromises latex condoms. Research has associated sex in thermal waters with higher rates of vaginal infections, UTIs, and thrush. Not worth it. 

A Hot Car

Synthetic seat fabric creates friction, heat produces ideal conditions for yeast growth, elevated temperatures degrade latex condoms, and there’s no bathroom access afterward. “It’s the combination of many factors that makes it a problem,” Dr. Whitton says.

Anywhere You Can’t Pee Afterward

Festivals, remote outdoor settings, anywhere a bathroom requires a ten-minute hike—all of these aren’t ideal. Urinating after sex flushes bacteria away from the urethra before it can travel to the bladder, and it’s one of the most well-documented ways to reduce UTI risk. The less convenient it is to do, the more it ends up getting skipped.

The one water option that gets a partial pass is the shower, where water runs off rather than pooling. The main risks there are slipping and reduced lubrication, both of which a silicone-based lubricant addresses.

As for your own home, Dr. Whitton says it’s one of the safest options from a vaginal health perspective. Familiar environment, familiar bacteria, immediate bathroom access. “It sounds obvious, but it’s worth saying out loud because ‘adventurous’ has become culturally synonymous with ‘better,’ and from a health standpoint, that’s not always true,” she says.