All components inside a spacecraft have two physical limits related to heat: operational limits and survival limits. Within operational limits, the component remains functional though its efficiency may vary within those limits. Beyond operational limits, some components have survival limits. If a component is outside its operational limits but within its survival limits, it can return to function in the event that its temperature falls back within the operational limits for that component. Should a component drift outside its survival limits, it will become permanently inoperable.
Reher, Michael T., and Bradley N. Koeppel. "Battery thermal control system and method." U.S. Patent 5,215,834, issued June 1, 1993.