Do you know why you get a fever when you are sick with a cold or flu? You get a fever because your body is working extra hard to fight off the invaders that are making you sick.
When God designed your body, he designed it to be able to fight off sicknesses, but how does this design work? God gave you an immune system that is trying to protect you. It tries to protect you in many ways.
Imagine your body is a castle. This castle is amazing, but sometimes sneaky invaders called germs try to get in. These germs can make you feel sick, like when you get a cold or the flu. But you have several lines of defense.
First, the germs have to get past the guards. You have several guards including your nose hairs, mucus in your throat, and your skin. These are all designed to keep germs out.
If the germs get past your skin, the next line of defense is the fever. Your body turns up the heat to make it uncomfortable for the germs.
In your blood stream float your white blood cells that form the army to defend your body. There are several kinds of white blood cells. There are granulocytes, lymphocytes and monocytes.
One kind of white blood cell is like a scout; it recognizes the germs and sounds the alarm. Other white blood cells are defenders; these attack the germs to destroy them. Still another kind of white blood cell is like a strategist. It produces antibodies that mark the germs and remember them for next time, so that if they see that germ again, it remembers it is bad and tries to attack it quickly. Finally, the last kind of white blood cell cleans up the mess after the invasion.
You can even give these guards a “head start” with a vaccine, which acts like a secret training camp where your cells study a practice version of a germ to learn exactly how to defeat the real thing.
So the next time you feel sick, remember that your brave internal army is hard at work keeping your castle safe!
God has designed your body to defend itself. It is amazing to think you don’t have to tell your body to defend itself—it simply does! Even while you are fast asleep or playing with your friends, your internal guards are constantly on patrol, watching over your health without you ever having to say a word.