misreading temp gauge

Car is new to me (2 weeks). Drove it home from San Diego with gauge showing 3/4 hot, but figured that it would escalate if there really was a problem - never did. I was planning on an overhaul/replacement anyway, just not sure what the deal was. The sensor is adjacent to the thermostat housing on the slant. I'm just getting over surgery; soon as I can get around not bent over, I'll try disconnecting the sender and see what the gauge shows then. Thanks for all the help, guys.