Science #49 – How Our Body Always Stays at 36.5°C: The Science Made Simple

 Have you ever wondered how our body keeps the same temperature—around 36.5°C (97.7°F)—even on a freezing winter day or in the middle of summer heat?

Our body maintains this temperature using an amazing built-in control system. Let’s explore the simple science behind it.

How Our Body Always Stays at 36.5°C

1. The Temperature Boss: The Hypothalamus

Inside our brain, there is a small but powerful area called the hypothalamus.
You can think of it as the body’s temperature control center.

It constantly checks our internal temperature.
If the temperature rises or drops, the hypothalamus immediately sends out instructions to bring it back to normal.

2. When Your Body Gets Too Hot

When we exercise, stand in the sun, or enter a warm room, our body temperature starts to rise.
The hypothalamus helps us cool down in two major ways:

✔ Blood Vessel Expansion (Vasodilation)

• The blood vessels near the skin become wider.

• More blood flows close to the skin surface.

• Heat escapes out of the body more easily.

✔ Sweating

• Sweat comes out through our skin.

• As sweat evaporates, it absorbs heat from the skin.

• This cools us down — like natural air-conditioning.

This is why a gentle breeze feels so refreshing on a hot day!

3. When Your Body Gets Too Cold

In cold weather, the hypothalamus activates the opposite strategy to warm us up:

✔ Blood Vessel Narrowing (Vasoconstriction)

• Blood vessels near the skin become tighter.

• Less heat escapes through the skin.

• This helps the body save its warmth.

✔ Shivering

• Your muscles quickly tighten and relax over and over.

• This muscle activity produces heat.

• It’s like your body is making its own “internal heater.”

This is also why rubbing your hands or stomping your feet helps you warm up — your muscles are generating heat.

4. A Truly Amazing System

All of these reactions happen automatically.
We don’t think about them — our body simply adjusts itself to stay alive and healthy.

Thanks to this smart temperature control system, we can survive in many different environments while keeping our core temperature stable at around 36.5°C.

📌 Quick Summary

• Hypothalamus = body’s temperature control center

• When hot → blood vessels widen + sweating

• When cold → blood vessels narrow + shivering

• Goal → keep body temperature near 36.5°C