The Ideal Gas Law.
Pressure and volume are inversely related. Temperature is related to both. This means that the more stuff you have, you either are putting it in a bigger space or putting it under greater pressure. This is why rockets, guns, cars and jets work. If you increase the pressure on your stuff but don’t change the volume, you are going to see an increase in temperature. This is why pressure cookers work.

I really enjoy Manhattan Special. It is carbonated, sweetened coffee and it tastes heavenly. Though it is called Manhattan Special, it’s very hard to find in Manhattan and very easy to find in Brooklyn. I recommend it highly, except for one caveat. When you buy a warm bottle of Manhattan Special, do not, however much you want to, drink it. Stick it in the fridge. Let it cool. Because the Ideal Gas Law applies very heavily to Manhattan Special. If you try to open it warm, the bottle will fizz and spit and shoot everywhere quickly. This is not because you shook it up or because this one bottle was extra fizzy. This will happen every time you try to open a warm bottle of Manhattan Special.

A chilled bottle will behave nicely and will not overflow. Chilled, temperature T is much lower, and correspondingly, there is less pressure p in the bottle of constant volume V. Opening the bottle, the delicious beverage will not try to expand to occupy as much space and you will not be covered in brown liquid, cleaning up your kitchen. This fact is brought to you by me paying attention in physics class.