In most cases, plants stop photosynthesizing in the low 90's, but that is not relevant info inside a package where they are receiving no light. For most plants, it would take a temperature well over 100 to kill the plant from cooking. I assume that plants in full sun are subjected to leaf-surface temps above 100 many days each year, for several hours at a time.
Starvation from more than 3 days with no sunlight can seriously damage or kill non-dormant plants, especially when combined with prolonged high metabolism / respiration rate, due to high inside-package temperature.