Engine overheating & a sticky shifter

I have a standard transmission 2002 Saturn SL2. While driving in 5 o’clock traffic, I came to a stop light and out of habit glanced over the gage cluster; nothing out of the ordinary. About a minute goes by before the light turns green and as I’m shifting into second gear I notice that the shifter is sticking, almost as if I didn’t have the clutch in. I look back down at the gage cluster and the Engine/Coolant light is flashing and the temperature gauge is trying to go beyond the red.

I immediately pull off the road and sit in a parking lot for about 20 minutes. I start it back up and keep an eye on the gauge, and it seems to be running a little hotter than normal, but nowhere near being in the red.

Since then, I’ve noticed that the temperature runs warmer than what it used to (normally at the first tick mark; it now runs between the first and second tick mark), and occasionally runs right at the second mark.

At first, I was thinking that the thermostat may have temporarily been sticking/not opening, causing that initial overheating. But the engine clearly runs hotter, making me wonder if it’s not the thermostat, but something else. I’m good with my oil. And am wondering if it could possibly be transmission fluid; but I don’t know if the sticky shifter is significantly part of the main problem, or just a result of the overheating, or possibly just a coincidence.

For the sticky shifter you should check fluid level in transmission