Taking warm showers on hot days isn’t just a myth: they actually cool your body down.
In a new video, Dr. Karan Raj, a UK surgeon and social media’s go-to doctor, champions this practice for bedtime benefits.
Warm showers cool down your core body temperature and lower your sleep threshold, says Raj. Warm water causes vasodilation–your blood vessels widen and blood pressure decreases–to ditch excess heat so you cool down faster, he says.
And there’s plenty of research to back Dr. Raj.
One study published in the Journal of Clinical Sleep Medicine found bathing in hot water before bed shortened sleep onset latency—the amount of time it takes to fall asleep after turning out the lights (1).
A 2019 review of 17 studies found taking a shower or bath in hot tub-like temps between 104 and 108.5 degrees Fahrenheit improves your quality of sleep. People who soaked one to two hours before bed also fell asleep faster (2).
On the flip side, cold showers in the morning raise your body temperature which make you more alert, says Raj.
Cold water also increases your heart rate and gets your blood flowing for better circulation and stimulates noradrenaline and beta-endorphins to boost mood.
This isn’t the first time we’ve shared Dr. Raj’s tips. He says to gargle water, sing, or hum for 10 seconds for instant stress relief. And whatever you do, don’t lift weights with your penis, he says. You set yourself up for penile fracture and erectile issues.