Car running hot all of a sudden, don't know what the cause might be..

First of check the coolant level, ensure it is correct. Check it when the engine is cold to avoid getting burned. When the engine overheats does it boil over and cause a loss of coolant? Do you hear the electric cooling fan turn on. There is a possibility that the engine cooling system thermostat could have failed.

Make sure the cooling fan is working, make sure the coolant fluid level is OK. Don't allow the engine to overheat, major damage will occur if it does. If you have to tow it to a shop, then it's worth the expense vs. a possible overheat. It's unlikely that the sensor is bad, possible, but assume that it is overheating until has been checked out.

You may have a bad thermostat or the radiator is clogged, check for any possible leaks at the waterpump You may have to perform a pressure test make sure the head gasket is not leaking and also check your anti freeze container on the fender well, there is a line for the level when its cold and when its hot. Does the electric fan come on?