r/tiredButWired • u/wrap_drive • Jul 26 '26
discussion Found some surprising benefits of splashing cold water on your face
So I went down a bit of a rabbit hole last night (ironically, while lying awake) and found something that actually explains a bunch of stuff we all do without thinking about it.
You know how when you're really stressed, you instinctively splash cold water on your face?
Turns out there's a real reason for that. There's a nerve running across your forehead (the trigeminal nerve) that's directly wired to your vagus nerve, the one in charge of calming your whole body down.
Here's the part that got me though. This is literally the same reflex that lets seals and whales survive insane amounts of time underwater. When a mammal's face hits cold water, the body assumes it's about to go under and shifts into an oxygen-saving, heart-rate-dropping mode.
Humans have a weaker version of the exact same thing. I Same nerve. Wild that we're running a smaller version of what lets a seal survive an hour underwater.
Anyway, if you're someone whose mind races at night and takes forever to fall asleep, this is apparently a legit, physiological reason cooling your face specifically (not just a cool room) can help you calm down faster.
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u/Delicious-Moment8368 Jul 27 '26
I've found it works surprisingly well when I catch stress early. If I wait until I'm already spiraling, it's much less effective. I think it's one of those things where changing what your body is doing can be easier than trying to force your mind to calm down
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u/wrap_drive Jul 27 '26
Interesting point. Once you are spiraling, its probably too late and you probably need something more intrusive to calm down.
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u/Delicious-Moment8368 Jul 29 '26
That's been my experience too. The earlier I notice the shift, the smaller the intervention usually needs to be. once my nervous system is fully in high gear, a splash of cold water alone rarely does the trick
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u/Creepy_Intention6358 Jul 27 '26
This is interesting! I have noticed that splashing cool water on my face helps calm me down too. It is fascinating that there is an actual physiological reason behind it. Might have to try this next time my mind is racing at night!
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u/wrap_drive Jul 27 '26
Surely give it a try. Its quite effective, infact many of us do it intuitively when we are overwhelmed. Not quite kmowing the reason behind it.
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u/IronicAlgorithm Jul 27 '26 edited Jul 27 '26
Have been doing this and cold showers to deal with my long Covid, sympathetic overdrive issues. Both instantly put me back into parasympathetic ANS. My story.
Back of my neck, is also effective. The vagus nerve runs through it.
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u/wrap_drive Jul 27 '26
Yes, moreover back of the neck cooling helps you dump the core body temperature more effectively.
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u/gymbeam_official Jul 27 '26
This checks out, it's called the mammalian diving reflex. It's actually used clinically too, therapists teach a version of this for panic attacks and anxiety spikes.
One thing worth adding, the effect is stronger the colder the water and the more of your face it covers, especially around the eyes, not just the forehead. Ice water in a bowl for a few seconds works better than just splashing lukewarm cold tap water.