The A/T Oil Temp Warning light came on last night on my 1996 Isuzu Rodeo. We had been in heavy stop & go traffic for about an hour. We had driven eight hours the day before & the oil level was ok. After the light came on, the coolant & oil levels were low, so we filled them. The light did not come back on.

There was no evidence of leaking fluids in the driveway, either before or after the light came on.

Do we have a problem? Should we have it checked out. Is it ok to drive?

I would definately do a engine coolant flush & a transmission pan drop & filter change. You need to keep up on these items with these trucks! The transmission relies on the cooling system for it's cooling, so if that's running hot, so will the transmission.
G/luck
Joel