Have an'05 Ram 1500 and recently noticed the temperature needle spiked to hot and "check gauges" light was lit. Ran it the next day for half an hour with no temperature jump. Any suggestions? Thermostat going?????

 

I would check all the usual things before going to the expense of replacing parts. Check to insure your Rad is clear and is clean. Run the garden hose to rinse the radiator fins.
Insure your coolant level is up.
Insure your water pump is circulating properly