1999 Jeep Grand Cherokee limited

96000 miles with the 4.7L engine. The heater is blowing only warm air once in a while.
Thermostat appears to be okay in that the engine temp goes to its usual operating temp of 210 and the 2 top radiator hoses along with the bottom one get hot to the touch.
I have a strong suspicion that this is going to be expensive.

Thanks. Mike