When we hand over a package to a courier service, we expect a safe transit of that package to take place, in accordance with some prearranged terms. When that package contains sensitive items, like certain vaccines, biological samples, or perishable foods, it is critical that a particular level of refrigeration be maintained continuously throughout the entire delivery process. Items such as these can be rendered ineffective or spoiled by excessive temperatures, but we have no insight into what actually occurs during shipping, so we do not have a simple way of determining if this has happened. These ruined products can lead to serious consequences, including illness and death, if they are not identified.
This is a companion discussion topic for the original entry at https://www.edgeimpulse.com/blog/a-cool-package-monitor