To get a genuine and high fever overnight, you will need to come into contact with a virus.
Most viruses don't last very long once outside the body, so you'll need to come in close contact with someone that has a developed viral fever already.
Even then, there's no guarantee that the symptoms will start showing in you overnight - as it depends on your immune system.
The weaker your immune system, the more likely you are to develop symptoms overnight.
The thing to remember when you're out there trying to pick up germs and disease is that fevers also don't go away overnight.
They usually last between 3-7 days depending on seriousness, and they will make you feel very bad indeed.
Also, if you're catching a fever on purpose - you could be putting yourself at serious harm or risk - with many people each year suffering serious consequences from being unable to fight off an infection.
So, all in all, catching a fever intentionally isn't a very bright thing to do at all!
But that's not to say it's impossible to catch a fever overnight, it certainly is...
But maybe there are better solutions to the problems you are facing? Why not speak to a parent and see if they can help?
Let's say you're facing some problems at school and just want some time off away from it all. Do you really think getting sick intentionally will solve your problems?
It will just delay them. But when you return to school after feeling terrible for a few days, you'll have to face the same problems you were afraid of in the first place.
Instead, there's a much more effective way of dealing with your problems:
Don't be afraid to ask an adult for help
Believe it or not, all adults dreaded going to school at one point or another when they were younger. Even the ones that say they loved school as kids have probably forgot how stressful it can be.
Instead of hiding it from them, you should open up and let them know exactly what the pressure is like.
I'm 28 and I remember feeling sick every time the school bus pulled up in front of the school gates, and wishing I could just stay on the bus and ride back home.
So if I can remember that kind of stuff, chances are your parents or another trusted adult will too. Even better, they will be able to give you experience and advice on how to deal with situations. Listen to them! They may surprise you :)