I have cooked Pinnacle Peaches. How soon must I eat them before they will no longer provide the bonus for being hot?
Food seems to remain hot for 100 in-game minutes (8 minutes and 30 seconds in real time).
I cooked a can of Pinnacle Peaches, then cooked other items while frequently checking the status of the cooked peaches in my inventory. The peaches kept the Hot status until 100 minutes had passed in the game, at which point they became Cold.
I was standing indoors next to a fire for the entire time. I do not know whether colder ambient temperature would have an effect on the food.