Why Does Sleeping With Your Feet Outside the Covers Help You Sleep?

Human beings are warm-blooded creatures. Yes, you heard that correctly.

So what does being warm-blooded mean?

It means that we can generate our own heat from our bodies, even when it’s cold outside. It’s not only cold that we can fight against, but also a myriad of other weather conditions: extreme heat, rain, snow and so on. Warm-blooded creatures don’t need to worry too much about the outside temperature and instead maintain their own temperature. As you can guess, cold-blooded beings are exactly the opposite in this regard.

In other words, temperature plays an important role in our survival… that much should be obvious. Among all of our body parts, feet are perhaps the most crucial when it comes to temperature regulation of the entire body.

How is that possible?

Thermoregulation: Producing Heat Within

Humans (or warm-blooded beings) have thermoregulation on their side. This is a process through which a human body is able to maintain its core temperature, irrespective of the temperature outside. The state when one of these creatures achieves a normal internal temperature is called homeostasis. Therefore, thermoregulation procedures and mechanisms ensure that the body attains homeostasis.

Thermoregulation is achieved mainly by burning energy, but there is a variety of physiological functions that also play a part in this process, such as sweating, shivering and overall skin blood flow, which contributes to the maintenance of core body temperature.

Heart and Blood Flow

The heart has a major role to play in maintaining body temperature. Blood flows from the heart to various organs through the arteries to all your cells and returns through your veins.

Human Circulatory System

Human Circulatory System

When outside temperature is high (hot), blood flows more freely, as blood vessels open up to allow more blood through them; on the other hand, when it is cold outside, vessels constrict a slightly, thus reducing the volume of blood flowing through them.

Now, many think that the head is the part of the body that receives and thus expels most of the heat from the body. However, that is not entirely true. It turns out that our feet are actually the best when it comes to getting rid of excess heat in the body.

Feet control Body temperature

Not only are our feet there to help us perform all kinds of activities, but since they are at a body’s extremities, feet help in releasing a lot of excess heat from the body.

Firstly, they have a large surface area and specialized blood vessels, which means that they can be opened up to a large volume, thereby allowing more blood to flow. Consequently, they can help in releasing heat more quickly from the body. When the temperature is normal, the blood vessels return to their normal size.

Since feet are at our extremities and don’t have much muscle, it means that they can cool down more easily than other body parts. Also, feet are (usually) devoid of hair, so the heat exchange can occur faster.

feet large surface area

Large Surface Area of foot

If you are biologically curious about this, let me tell you that feet also contain things called arteriovenous anastomoses, which link arteries and veins before they meet in blood capillaries. When it’s hot, these anastomoses dilate and allow more blood to flow through blood vessels.

Funny Behavior of Our Feet

Have you ever noticed that your feet (and sometimes a large portion of your legs) come out from below the covers when you’re deep in sleep?

This is because when you are asleep, your body produces a lot of heat. The heat is exaggerated due to the covers above you. In order to maintain an optimal temperature and prevent your body from overheating, your tiny little soldiers sneak out of the covers and provide you with some unconscious relaxation. Have you ever thanked them for that?  In fact, it has been repeatedly seen that people sleep more soundly when their feet are protruding from the covers.

Therefore, be thankful to your feet. In fact, be thankful to every part of your body, as each part is functioning for you at all times, even when you’re busy enjoying those beautiful dreams.


  1. Thermoregulation In Humans – Wikipedia
  2. Circulatory Anastomosis – Wikipedia
  3. Homeostasis – Wikipedia
  4. University of Wollongong Australia
  5. Healthy Sleep
  6. Medical Daily
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Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spends a lot of time watching movies, and an awful lot more time discussing them. He likes Harry Potter and the Avengers, and obsesses over how thoroughly Science dictates every aspect of life… in this universe, at least.

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