Thank you everyone. I happen to have an IR thermometer and will do as you said. The car also clearly needs a tune up as it appears to be misfiring somewhere. I just purchased it so I'll have to go through it.
I bit my lip to withhold mention of head gasket failure. Then you went and mentioned a skip.
Fill the radiator , leave the cap off and let it idle. Watch for a continuously repeating air bubble. Good luck