Give it a sniff and put it in the fridge. You can make cheese if you have rennet but it may be a bit more sour than you are used to. I purposely did this last summer to make a batch of cheese with "wild" cultures, just to try it. It is called "clabbered" milk. You can also use it in any recipe calling for sour milk, buttermilk, etc, or any recipe that uses baking powder, as the acidic milk will make it work better. You can put it in recipes not calling for sour milk...use it as the liquid in bread.
I wouldn't bother pasteurizing it. Pasteurized milk left out will sour then rot rather quickly, but the good bacteria in raw milk will protect it most of the time. I'd use it up quickly, though, and sniff it each time just to be sure it is pleasant sour and not "bad," especially if it takes you a few days to bake with it.
Or you could freeze it in portions that match you favorite recipes, like buttermilk pancakes or biscuits, if it is too hot to cook with it right now.