I've got a slow leak in my coolant hoses which requires me to top off
the coolant levels every week (Until I can get it fixed). I've noticed
the engine to be running slightly hotter than 210 on average even
though its 20-30 degrees here in the Boston area. This morning I
refilled the coolant bottle, started up my car and went back inside for
5 minutes while the car warmed up. When I started driving the car I
noticed the temp gauge to be between the 210 and 260 mark. Since the
engine showed no signs of overheating I was puzzled. All of a sudden
the temp gauge surged to 260 and the "Check engine Light" came on. I
pulled over and waited for the steam to come pouring out of the engine,
which never happened. The funny thing was all the fans were working.
I turned off the car, let it sit for a while and turned it back on.
When the engine warmed up it was back to 210 again and showed no signs
of moving above that.

What could be the cause? Clogged lines?

97 Cherokee Sport 4 x 4.