Body & Senses
Why do we sweat?
After their walk, a shady bench becomes the favourite place.
The short answer
Sweat reaches the skin from small glands. When it evaporates, it takes heat away and helps cool you. Sweat alone cools less effectively when it cannot evaporate.
An imagined Wusel scene
Puschel and Flauschi investigate
After a walk they sit in the shade. Puschel rests a little towel on his lap. Puschel“My paws are ordering a break.”
Flauschi puts down her water bottle. Flauschi“They can have one. Sweat also helps people cool down.”
Puschel“Is it like a tiny shower?” Flauschi“Not quite. Heat is carried away especially when sweat evaporates from the skin.”
Puschel“So nobody needs to run faster and faster?” Flauschi“No. We can explain this without overheating.”
They sit for a while. The next part of the path will not run away. Today a break suits them better than a race.
Little Wusel quiz
When does sweat take heat away from skin?
Choose one answer: a), b).
- a)When it evaporates.
- b)Only when it stays there as drops.
Show answer
Correct answer: a): When it evaporates. Evaporation carries heat away.
Must we deliberately get sweaty to explore this?
Choose one answer: a), b).
- a)Yes.
- b)No.
Show answer
Correct answer: b): No. No. Talking about it and finding shade is enough.
Word help
- evaporation
- Liquid becomes gas at its surface, even without boiling.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
The body produces heat
Working muscles also release heat. If the body gets too warm it can release more sweat onto the skin.
Evaporation needs energy
Sweat is mostly water. Changing liquid water into vapour needs energy. Some comes from the skin as heat, helping it cool.
Water needs replacing
Sweat sitting on the skin is not the whole explanation; evaporation matters. Sweating loses water. Drinks, shade and breaks help you look after your body in warm conditions.
Why evaporating water cools skin
Evaporating sweat changes liquid water into invisible water vapour. This needs energy, including heat from skin. Evaporation therefore matters for cooling. Sweat evaporates less readily in very humid air. A wet shirt alone does not prove sufficient cooling. Adults help with drinks, shade and rest; no heat experiment is needed.
References for this explanation: [1]
The key points again
Discovery 1
People make sweat in small sweat glands in the skin. Glands are body parts that make and release particular substances.
Source: [1]
Discovery 2
When sweat evaporates from skin, it takes heat away. Evaporation means liquid water becomes invisible water vapour.
Source: [1]
Discovery 3
Sweating makes people lose water. Drinking and taking breaks help in warm weather. Excitement can also cause sweating; sweat does not always mean exercise.
Source: [1]