This may sound dumb, but I learned the hard way: be certain to have coolant in your radiator.

I have a slow leak in my radiator/cooling system for my Jeep (or should I say "I had", because now the leak is massive!), so I was checking it every few days to see if it was low. I would pop open the radiator cap and, if I couldn't see any liquid, I'd add water and be on my way.

Since I was adding water just a little at a time, it never occurred to me that I would also need to add coolant.

Water will work fine in a radiator, but only up to a certain point. Coolant (a mixture of distilled water and alcohol) works much better at absorbing heat than water. If you run straight water in your coolant for too long, you're not going to have a good time.

I am not having a good time right now. My Jeep overheated this week to the point of splitting open the radiator. I'm a big dummy: had I added coolant each time it was low, I would have avoided this situation. And to go one step further: had I looked into getting the leak repaired...

But, alas, I digress - I'm now in the midst of changing my radiator, associated hoses, and thermostat.

If you are experiencing a leak in your engine's cooling system, GET IT FIXED! Until you get it fixed, remember to add coolant instead of water!