fun story. I know a guy who designed a high precision refrigerator for storing vaccines. These fridges need to be able to maintain temperature to within some re

fun story. I know a guy who designed a high precision refrigerator for storing vaccines. These fridges need to be able to maintain temperature to within some relatively small margin to avoid destroying the vaccines, and they needed to be able to withstand extended periods of no power since they would be stationed in places with questionable infrastructure. The main solution was to use a large water reservoir, it would "store most of the cool" while the power was out, also helped a lot with keeping the temperature stable when there was power.