most likely it will be hot so put snow on it
Open the radiator cap when the engine is cool, check the radiator's fluid level, and add appropriately. NEVER OPEN A RADIATOR CAP WHEN THE ENGINE IS HOT OR OVERHEATING. Check your car's owner's manual for specific details.
Do it when the car is cold if the radiator is hot fluid may be forced out when you take off the cap.
The cooling system is under pressure and opening the cap can spray you (and other things) with very hot coolant.
Hot water in the radiator is under pressure and can burn you.
Try a new radiator cap.
a bad termastat
radiator fan, head gasket,
The most common reason for overheating of a car radiator is that there is not enough water in the radiator. Radiators can lose water in a variety of ways, and often need to be refilled. The other possibility is that the water is not being circulated properly. I should add that cars do heat up quite a bit in the sunlight on a hot day, which adds significantly to the chances of overheating the radiator.
It can mean that the temperature is too hot or you have a bad radiator cap.
no cap, it is filled through over flow tank on right hand side of car. it has a cap, do not remove if hot.
A radiator cap can not only be hot, but it is holding in pressure. When the cap comes off under pressure, hot antifreeze will spray out, possibly causing injury.
if your engine is running hot and its not your radiator you probably need to burp it to get the air out from the hoses and radiator, that should take care of the overheating problem, if it doesnt pressure test your hoses and raiator you might have a collant leak creating hot spots