Christine Drews Sieger
A freezing-cold shower before bed may actually trap body heat and make it harder to sleep, experts warn.
Taking a freezing-cold shower seems like the perfect fix when you feel overheated. Throwing yourself under icy water actually triggers a sudden biological shock.
That sharp temperature change causes your body to release stress hormones like cortisol and adrenaline, boosting alertness right when you need to relax.
Beyond the sudden wave of stress, intense cold disrupts your body’s natural cooling system. Human skin relies on expanding blood vessels near the surface to release excess thermal energy into the air, according to The Guardian.
“The last thing you want to do is go into a freezing-cold shower”
Mike Tipton, a professor of human and applied physiology at the University of Portsmouth.
“If you’re trying to go to sleep, the last thing you want to do is go into a freezing cold shower.” He added, “What you do then is you trap the heat inside the body,” he explained to The Guardian.
He pointed out that sudden exposure to extreme cold forces those outer blood vessels to shrink immediately, shutting down surface circulation.
Warmth stays trapped inside your core instead of escaping into the room. He added that such a physical reaction is “just about the last thing you want before you go to bed.”
Choosing Tepid Water
While sudden cold immersion plays a vital role during life-threatening heatstroke emergencies, routine bedtime cooling requires a much gentler routine.
Body heat escapes efficiently only when blood flows freely toward your skin.
To keep that natural heat release moving, experts suggest stepping under lukewarm water instead.
The physiologist recommends turning up the temperature instead, so the water feels lukewarm – preferably around 25–28 degrees Celsius.
This keeps blood circulation open in the skin, allowing body heat to continuously escape into the room, The Guardian reports.
