Warm weather 460 problems

Problem occurs in warm weather. engine loses power, hesitates and stalls. Won’t start until engine cools, sometimes 1/2 hour. Problem is worse in traffic or mountain driving.

1992 Airstream class B motorhome. Started in AZ climing moutains in the Tonto Basin and repeated a few times in the moutains of Or, Wa,. Semms to be getting worse now; happened last week in Odessa TX in 80 deg. temps. in traffic. Ran ok after getting out of town. Also noticed the fuel consumption is getting poor. Help, let us know if you solved the riddle.