1997 Dodge Intrepid Overheating

I was driving down a road going 45, everything was fine one minute but it seemed like the next minute when I looked down my temp light was on and if the needle could have gone any farther up it would have.
No fluids are leaking anywhere. I checked the oil and there's no coolant mixing so hopefully its not a head gasket. The fans come on while driving but not when the key is in the on but not turned over position. I replaced the radiator, water pump, and timing chain 20k ago (still under warranty)

**Note** Last week my check engine light came on and it was running alittle rough. I noticed one of my spark plug wires was loose. When I looked at it I noticed the spark plug was loose. I replaced all 6 with new OE platinum. The car was running fine but the engine light was still on. A friend told me that I just need to reset the computer.
Could the check engine light have been for 2 separate problems and I just corrected one?
(Thermostat and Spark don't seem to go together tho) Any thoughts or suggestions before I make a put any money into my work horse would be appreciated.
Thank you
Tj