When temperatures reach 90 degrees and the humidity makes stepping outside feel like walking into a sauna, it seems smart to end your shower with a splash of cool water. But is bathing with cold water good for you? Conveniently, cold showers are one of the easiest ways to enjoy the craze of cold water immersion (CWI)—no cold water baths or deep freezers full of ice bags required in the backyard. But besides cooling you down, is taking a cold shower actually good for you? And do the purported benefits—improved focus, better mood, stronger immune system, even higher testosterone—really hold up?
Some of these claims are rooted in science. Others, not so much. Further, MDs help us separate fact from fiction.
What effect does a cold bath have on the body?
If the cold shower feels intense then you are not weak. Your body is just shifting into high gear. “Exposure to cold water triggers an immediate sympathetic nervous system response,” says Arash Bereliani, MD, FACCA board-certified cardiologist, internist, and medical director of the Beverly Hills Institute for Cardiology and Preventive Medicine. “Your heart rate increases, breathing deepens, and the body releases norepinephrine,” a neurotransmitter that constricts blood vessels and increases alertness. That immediate shock is what triggers many of the effects associated with CWI.
Benefits of cold showers
Staying cool on a hot day is a clear win. But the benefits of cold showers go beyond this. According to Dr. Bereliani, the most well-documented benefits are improvements in mood and mental alertness—which is probably not surprising to anyone who has experienced the immediate rush and sense of accomplishment from taking a cold shower. “Exposure to cold increases norepinephrine levels significantly, which has real effects on focus and mood regulation,” he says. Florence Comet, MDAn endocrinologist and longevity expert, says cold water also increases dopamine levels, which doubles the attention-enhancing and mood-boosting effects. Since exposure to cold trains your stress response, consistent dosing also has the potential to improve emotional resilience over time. a study A study from 2007 also found that regular cold showers of just two to three minutes – about 68 degrees Fahrenheit – could help reduce depression symptoms.
If your sleep score could use some use, a cold shower might nudge your numbers in the right direction. “Some people find that taking a cold shower before bed helps them fall asleep faster and get deeper sleep,” says Dr. Comite. Cooling your body at night helps lower your core body temperature, setting the stage for relaxation and a good night’s rest.
Cold showers can also boost your immune system by stimulating white blood cells to defend against viral infections, says Dr. Comite. she quotes a study A study in 2016 found that people who took short, cold showers — just 30, 60, or 90 seconds long — reported 29% fewer sick days from work than people who only took hot showers.
Then there is metabolism. Dr. Bereliani says cold activates brown adipose tissue, which plays a role in metabolism and thermogenesis. As your body works to stay warm, it temporarily increases your metabolic rate. It’s enough to burn a few calories, but it won’t take the place of a clean diet or a solid workout.
Does taking cold water bath increase testosterone?
If there’s one claim that’s guaranteed to grab men’s attention, it’s that cold showers can naturally boost T. Despite the hype, don’t treat them as cheat codes for your hormones.
“Some animal research suggests that cold exposure may help testicular function, because the testicles are sensitive to temperature, but we don’t have strong human data showing that cold showering meaningfully increases testosterone levels,” says Dr. Bereliani. a 2026 Study Saw it firsthand: 11 current or former male college athletes took 10-minute cold showers for four consecutive days. Some recorded higher testosterone levels, some lower, and some showed negligible change. Bottom line: Cold showers caused no statistically significant changes.
