Why Do We Generally Feel Cold After a Bath?

Have you ever stepped out of a warm bath, dried yourself with a towel and suddenly thought, “Why am I feeling cold?”

It can seem strange. You were sitting in warm water, so shouldn’t you still feel warm?

The answer has a lot to do with evaporation, heat transfer and the way your body controls its temperature. These simple science ideas explain why getting out of a bath can sometimes give you a sudden chill.

Your Body Is Always Trying to Stay at the Right Temperature

Your body works hard to keep its internal temperature within a safe range. This process is called thermoregulation.

When you become too warm, your body has ways of dissipating heat. One important method is sweating. When sweat reaches your skin and evaporates, it removes heat from your skin and helps cool you down.

When you become cold, your body can do almost the opposite. Blood flow near the skin can change, and you may shiver. Shivering makes your muscles contract and relax quickly, producing extra heat.

So, your body is constantly making tiny adjustments to keep you comfortable.

What Happens During a Warm Bath?

When you sit in warm water, heat moves from the water to your body.

Your skin becomes warm, and the warm water can make you feel cosy and comfortable.

A warm bath can also increase blood flow towards the surface of your skin. This helps your body release some heat from its warmer inner parts towards the skin.

While you are in the bath, the surrounding warm water prevents you from losing heat as quickly as you might in cool air.

But then something important happens…

You get out!

The Air Feels Much Colder Than the Water

The air around you is usually much cooler than the bath water.

Imagine sitting in comfortably warm water and then suddenly standing in a cool bathroom. Your wet skin is now exposed to the air.

Water on your skin begins to evaporate.

And evaporation is a very important part of the explanation.

Evaporation Has a Cooling Effect

Evaporation happens when liquid water changes into water vapour.

But changing water from a liquid into a gas requires energy. Some of that energy comes from heat at the surface of your skin.

As water evaporates from your skin, it carries some heat away.

This is why sweat can cool you down on a hot day. The same basic idea happens with the water left on your skin after a bath.

You may have noticed something similar if you have ever had wet hands and stood in front of a fan.

Moving air makes water evaporate faster, and your hands can suddenly feel chilly.

The same thing can happen after a bath.

Why Does a Towel Help?

This is where your towel becomes your best friend!

When you dry yourself, the towel removes most of the water from your skin.

That means there is less water available to evaporate.

Less evaporation means less cooling from evaporation.

So, you normally start feeling warmer again quite quickly after drying yourself and putting on warm clothes.

This is also why walking around with wet hair can sometimes make you feel chilly. Water on your hair and skin can evaporate into the surrounding air, taking heat with it.

What About the Bathroom Air?

The temperature and airflow in the bathroom can also make a difference.

If the bathroom is warm and there is not much air movement, you may not feel very cold after your bath.

But if the room is cool, or there is a draught, the water on your skin can evaporate more easily.

Moving air can also carry away the moist air close to your skin, allowing more water to evaporate.

That can make the cooling sensation stronger.

Why Do We Sometimes Shiver?

If you feel particularly chilly, your body may respond by making you shiver.

Shivering is an automatic response. Your muscles rapidly contract and relax, producing heat.

It is one of the ways your body tries to raise its temperature when you feel cold.

You might also notice goosebumps when you feel cold. These are another automatic response controlled by your nervous system.

Usually, a brief chill after getting out of a bath is your body’s normal response to the change in temperature.

Does a Hotter Bath Always Keep You Warmer?

Not necessarily.

A very hot bath may feel wonderfully warm while you are in it, but it is not a good idea to make bath water excessively hot.

Very hot water can dry or irritate the skin, and hot baths can sometimes make people feel dizzy or weak. Health professionals generally recommend warm rather than very hot water.

A comfortable, warm bath is usually a better choice than trying to make the water extremely hot.

Why Does a Bath Sometimes Make You Feel Warm Afterwards?

There is an interesting twist!

Although you may feel cold immediately after getting out, a warm bath can also help you relax and may influence your body’s temperature as you cool down afterwards.

Warm water brings heat towards the skin. After the bath, the body can gradually lose that heat to the surrounding environment.

This natural cooling process is one reason a warm bath or shower before bedtime may help some people relax and prepare for sleep.

So, the bath can make you feel warm first, chilly for a short time afterwards, and then comfortable again once your body settles.

A Simple Experiment to Understand It

You can understand evaporation with a very simple everyday observation.

Put a small amount of water on the back of your hand and leave it there.

At first, your hand may feel wet.

As the water begins to evaporate, you may notice that the area feels cooler.

Now imagine having water over a much larger area of your body after a bath.

There can be a much bigger cooling effect as that water evaporates.

That’s the same basic science behind the familiar post-bath chill.

Why Does This Happen More in Winter?

You may notice the effect more during colder weather.

In winter, the air around you is usually cooler. When you step out of warm bath water into a cool room, the difference between the water and air temperatures can be quite noticeable.

Your wet skin is then exposed to cooler surroundings, and evaporation can make the skin’s surface feel even colder.

This is why having a towel and warm clothes ready can make getting out of the bath much more comfortable.