Ooh! What a great dodge ball games, Squeaks.
You must have been practicing your dodging.
噢我的天 我在流汗 这很合理
Oh boy, am I sweaty, which make sense.
When your body gets too hot,
like from the temperature outside,
or from exercise that makes you sweat.
Sweating is when your body lets out
a little droplets of liquid through your skin.
Even if it makes your feel kind of sticky and gross,
sweat can be a good sign
that your body is doing its job.
It’s how you keep you temperature down.
Human bodies work best around 37 degree Celsius,
or 98.6 degree Fahrenheit.
If your brain notice that your body is getting warmer,
it sends a message to your sweat glands
and tells them that you need to sweat.
Sweat glands are long coiled up tubes
that are in the dermis layer of your skin,
a little bit under the surface.
The sweat is made in the dermis,
that leaves your body through tiny openings called pores.
You can sometimes see these pores,
if you look really closely at your skin.
When the sweat dries or evaporates into the air,
some of the heat from your body escapes into the air too,
which helps you cool off.
You can try it right now for yourself if you want.
Just splash a little water onto your arm.
Even if the water isn’t cold,
you’ll start to feel your arm get colder as the water dries off.
We each have around 3 million sweat glands.
Most of them are called eccrine sweat glands,
which are all over most of your body,
especially on the pores of your hands,
the bottoms of your feet and your forehead.
You also have about two thousand apocrine glands,
which are in places like your armpits.
But they won’t start sweating until you get a little older.
Your ecrrine glands are the ones that get excited
when your brain senses your body temperature getting too high,
like when you are playing dodge ball, for example.
They’re also connected to signals from your emotions
in addition to your body temperature.
So if you’re about to do something that makes you nervous,
like getting up and making a speech,
that might make you sweat, too.
The sweat released by the eccrine glands
is made mostly of water,
with very small amounts of other chemicals mixed in.
Those other chemicals are why sweat tastes salty.
Some people don’t sweat much,
and some people sweat a lot.
It can depend on lots of different things,
including how big you body is,
how use to excrcise you are,
and just differences between people.
Some very sweaty adults can produce
up to 2 or 3 liters of sweat per hour.
And humans are the sweatiest animals around.
Lots of animals sweat,
but most don’t produce large amounts of sweat
to keep them cool the way that we do.
Some animals like dogs stay cool by panting instead,
which helps water evaporate out of their mouths.
A very long time ago,
when humans were just getting started,
they were developing big brains,
and living out in the open under the sun.
And having more sweat glands than other animals
help keep their bodies and their big brains nice and cool.
You sweat at least a little bit every day,
even if you haven’t exercise or gotten too hot.
And even if you don’t feel like you’re sweating,
it just means it’s drying off before you notice it.
And if you are sweating enough to notice it,
it’s extra important to make sure you’re making up for it
by drinking plenty of water.
Our bodies need lots of water to work properly,
and you lose some that water when you sweat.
So sweating might not always feel comfortable,
but it means your body is doing a good job
of keeping you cool.
And that is the time to drink some water and hit the showers.
You first, Squeaks.
Thanks for joining us.
Do you have any questions about sweating,
or how our bodies work or anything at all?
We have a website where you can send them to us.
Just ask a grown-up to help you
go to Patreon.com/SciShowKids to check it out.
Thanks. I’ll see you next time here at the fort.