Anecdote time: I used to live in a desert in the American Southwest and kept our bikes in the shed out doors. My brother had a Trek 1000 at the time and would blow a tire in storage any time the outside temp was above 100*F or so (goodness only knows how hot inside the shed, 140*F+ ?). To solve the problem he finally bought a higher quality tube and then reduced the PSI by about 10-15lbs. Not sure exactly which one solved the problem, or a combination of the two.