Shivers are reflexes which are things your body does automatically to keep you safe and healthy. Reflexes are controlled by your nervous system, which is made up of your brain, your spinal cord, and lots and lots of little nerves that stretch out all over your body. Nerves are like little strings or wires that carry information.

What kind of information?
Well, your nerves sense that the cool water of the lake has lowered your body temperature. Your body needs to stay at a toasty 98.6° Fahrenheit (37° Celsius) for you to be safe and comfortable. The nerves send signals saying, "I'm cold! Warm me up!"
Muscles in Action
That's when things really start to get
interesting. The signals go to your brain
(telling you to wrap in the towel) and to
your spinal cord, which sends a message
to other nerves all over your body. What
happens next? Your muscles tighten and
loosen really fast. Why? They're trying to
warm you up, just like taking a jog around
the lake would do. Once you get all snug
and cozy in your towel and your body
warms back up, your brain and nerves tell
your muscles to stop shivering.
There are other times when you might
shiver, too. Sometimes you'll shiver when
you're excited or afraid. When you feel
these things, your brain and nerves send
out messages through your body that
cause your muscles to get excited, so you
shiver.

Interesting

Ok

Datz nyc. Tank u

Front page things... Everyone needs to read this

Simply response to stimuli, nice one