A temperature excursion is any period when stored goods move outside their required safe temperature range. In food, medicine, and other cold-chain environments, even a short excursion can make products unsafe, reduce quality, or force disposal. The key issue is not just the temperature itself, but how long the goods were exposed and whether the limit was exceeded enough to break storage rules.
In cyber security, temperature excursions matter because attackers can target refrigeration and other operational technology systems that control setpoints, alarms, defrost cycles, or compressor timing. If those controls are altered, inventory may warm up without an obvious physical break-in. Defenders watch for unexpected setpoint changes, alarm suppression, and remote-access abuse, and they use manual temperature checks and disposal procedures when a control incident is suspected. In practice, a temperature excursion turns a digital compromise into a physical loss event.