What’s Happening in Your Body When You Enter Cold Water?

Your body has between 10 and 30 times more cold receptors than heat receptors in the skin. That’s a clue from evolution: cold is a bigger threat to survival than heat. When you step into cold water—especially if you’re not acclimatised—your body reacts fast.

Here’s what happens:

 Cold Shock Response (0–60 seconds):

Your skin receptors send an emergency signal to the brain: "It's cold, and we’re in danger!"

The brain hits the panik button: You activate your fight or flight response "We are dying!" your brain tells the body!

Closes capillaries near the surface and the vessels in the limbs..to hold in heat

Releases a mix of hormones and neuro transmitters : adrenaline, noradrenaline, cortisol, and even oxytocin (yes, the cuddle hormone!)

You gasp, heart rate spikes, and blood pressure rises muscles are activated-  because your body thinks you are gonna have to run away from the danger- "action stations we need to get out of here!" says the brain.. but then something curious happens..

 You chill out network then starts to activate....You rest and digest system kicks In (after  about 30-60 seconds):

The 'chill out' network (parasympathetic nervous system) tries to stabilise things telling your body "Hey we are not dying we are in cold water!"

Heart rate and breathing slow down

Blood pressure drops back down. 

You might feel calm (lack of blood to the brain!), alert (adrenaline), even euphoric (that's the oxytocin)

But this dance between the stress response and the calm response can be risky if your body’s not used to it. The nervous system ends up flickering between “ Life is in danger” and “ Actually, all chill here,” which, in rare cases, can cause arrhythmia (irregular heartbeat).

The best way to manage this is to build up acclimatisation slowly.

Cold water immersion will make you feel calm, focussed, energized and on cloud nine because of all of these stimulating hormones and neuro transmitters.  When you come out of the water and into the sauna- recognise this feeling, and then feel yourself coming back to your chill out state as the heat envelopes you...try to just sit and let those chemicals course through your body- enjoy the high and the coming back to earth. 

 Over time, with regular dips, your body gets the message: “It’s cold—but we’ve done this before and we didn't die last time!.” That’s habituation —your fight-or-flight response lessens, your system adapts, and you become more efficient at handling the chill.... but you still get all the benefits...which I will talk about next!