Fruits and vegetables are && alive, but after harvesting can no longer receive nutrients from their parent plant; they must rely on stored reserves to live. The temperature of the storage environment affects how quickly apples respire ("breathe"). Lower temperatures reduce this respiration rate and the time to ripen (and subsequently over-ripen) is increased. Lower temperatures also inhibit the growth of fungi and bacteria which may degrade or spoil fruits.

Heat speeds up most chemical reactions. The 'rule of thumb' is that the chemical reaction will be twice as fast when the temperature increases 10 degrees. Those are degrees C [Centigrade].

Molds and bacteria grow faster when the temperature is warmer, so warm fruit will rot sooner.

In general, I would say that an apple will rot faster in warmer temperatures. Rotting is the result of bacteria and fungi growing in the food, as well as a series of chemical processes which occur after the fruit is picked. All of these processes are generally slowed down when it is cold. This is why refrigerators are so good at keeping food fresh for longer! If the apple is very hot it may be too hot for bacteria to grow, however this will likely cause the apple to become mushy and soft as the fruit cooks.