Many basic science labs that use viruses as tools in their research will refrigerate or freeze them for longterm storage. The cold temp helps maintain their viability.
A couple of sentences stood out: In general, coronaviruses are very stable in a frozen state according to studies ofother coronaviruses, which have shownsurvivalfor up to twoyears at -20°C.
Specifically, coronaviruses are thermolabile, which means that they are susceptible to normal cooking temperatures (70°C).