A/C Problems w/Durango 2001

I have a 2001 durango 4x4. Right now after it warms up the temp gauge goes about 3/4 way ot the right and the check gauges light comes on. Then when I turn on the A/C the passenger side gets cold, however the driver side is so hot.

Any ideas' ?? I am thinking about changing the thermostat ??

Thanks