Sometimes you must do things in life that you dont want. There are several things you can do to make these occasions more bearable.

[edit] Steps

Wear comfortable clothes. If you are too hot or too cold, you will be unable to relax, and the situation will be worse. If possible, wear loose fitting clothing that will keep you warm, but not hot.
Imagine all kinds of ridiculous possibilities that would make your experience hilarious. Don't be afraid to laugh out loud when you come up with something funny, and sharing ideas with others around you may also be good.
When possible listen to music that fits the situation. If studying for a test you could try classical music to inspire you, or if working outdoors you might want to listen to something faster that can pump you up. Or if you're in a situation in which you can't listen to music, make some of your own--whistling, humming, or tapping a lively beat with your feet are great ways to calm yourself down and brighten other people's day.
If possible get buzzed beforehand by drinking a quality, high-proofed alchohol. Do not get drunk however--that can turn a uncomfortable situation unbearable. Drink just enough that you will be able to sit still, but still be able to zone out and have a positive outlook. And remember not to drink alcohol if you are underage! Also, know your limits: if you are prone to addiction, be careful!
Just get through it! Nothing lasts forever.