Under the heating of a piece, one understands the stuffy maturation (the spoilage) of shot game due to heat accumulation in the carcass. Pieces heat up especially when they are not opened in time. But the factors of location and size of the exit wound, time, outside temperature, and season also have a small or larger influence on whether and how quickly the piece heats up.
Especially with larger and fattier pieces, the insulating fat layer under the skin/hide causes a delay in cooling. Therefore, it is particularly important with such pieces to ensure that enough outside air can enter the game body shortly after it has been opened following the shot, allowing it to cool down. For this purpose, so-called ventilation slots can also be made in the leaves.
In the worst cases, i.e., with massive sunlight, high outside temperature, and unfavorable exit wound location, a piece can already be heated after 90 minutes. Therefore, heavy pieces that do not die in sight should also be searched for promptly so that the good game meat can be preserved.