temperature

I need some advise please. Recently this happens. During warm up and idling in the yard, the coolant temp indicator points straight down or back if you will. It fluctuates a little over and under the temp symbol. However when riding the needle points to the second marker on the gauge. Isnt that...

ok so when I get to this point, how do I get inside? I see where everything disconnects.

Just bought a 1995 with 14k miles on it. In wonderful shape. Road a couple hundred miles this weekend (wow is that easy to do) and watched the temp gauge go from almost all the way cool-left to past the mid point of green. Never got in the red even though it was pushing 90 out. But when I am...