Loses power when outside temperture gets around 95 degrees

I have a problem with my 03, 6.0, 5 speed auto, F350, crewcab, longbed, it loses power when the outside temperature gets above 90+ degrees. Taking off from a stop it starts away just fine but when it should start accelerating it just barely creeps along accelerating very slowly. Instead of the torque pulling the truck up to speed the motor revs up over 3500+ rpms before it shifts and it still accelerates very slowly. When it gets up around 60mph it seems to get back to normal and accelerate normally from then on. When the temp drops back down below 90+ degrees everything returns to normal, it doesn't matter if the air conditioning is on or off, it still doesn't want to accelerate. Everything else works fine and it starts and runs perfect until the temp rises above 90+ again. Any ideas, I'm thinking possibly the ICP but I don't know if that covers acceleration factors. /ubbthreads/images/graemlins/shrug.gif Thanks