With all the current posts about overheating I was reminded of my own lack of preparation - when I was working on the thermostat and upper hose, I managed to soak the front fender in hot coolant. Left untreated, this "ate" into the paint, big white colored splash and drip marks, etc. SHOULD have covered the fenders beforehand. SHOULD have wshed it off at once. I waited maybe 2 - 3 minutes before washing it off. Weeks later finally got around to using a good grade compound, Meguiars "Ultimate Compound", and an electric buffer. Cleaned up 98%.

Moral: Hot coolant comes out a whole lot faster than you are planning on...

 

Added pix - and that product would be the "Mirror Glaze"

 

NEVER EVER NEVER OPEN A HOT COOLING SYSTEM!!!!!!!

That coolant is 200*F and it WILL melt your skin off!!! You will spend days in the hospital possibly getting skin graft's.

I was burned by hot coolant when I was a teenager, the radiator cap came off of my overheating Catalina and soaked my t-shirt, when I pulled the wet shirt away from my chest skin came with it.
I have a scar on my chest, I was 18, I'm now much older.
It was very very very painful, having the bandage changed once a day at the hospital and the wound cleaned, half of my chest was burned.
Please let the engine cool at least 20 min before working on the cooling system.