My transmission temp and coolant level rise when idling. I've noticed it a couple times, all when pulling a trailer. Temps are normal, trans around 170 and coolant between around 190 - 200 while towing. When the truck is put into park and sits idling for about 5 minutes the transmission temp rises to above 180 and coolant to 205. The temps return to normal fairly quickly once I'm back on the road. I've had this happen a couple of times and wondering if this is normal or if anyone else has seen it.