Running hot

First, make sure you shut the engine off before it reaches the red. And don't continue to let it get that hot or you'll blow a head gasket.

Next check cooling system for a blockage (flush) and that it holds pressure (including radiator cap). Next check belt tightness, then thermostat working. (When engine reaches normal temp, feel both bottom and upper radiator hoses. Both should be hot or thermostat isn't opening. Next check that the fans are coming on during this time.

If all of these check out good, then check for a blown head gasket. The symptoms are not always the same, depending on where the gasket blew. Sometimes coolant will be dumped into oil, sometimes not. Sometimes exhaust gases will be forced into coolant only under load and when the engine is hot. (Because the heat causes the metal to expand, opening up the blown part of the gasket)