I stopped at a local grocery chain Thursday to get a meal at the deli. I noticed no customers had

[Igel]

63. Heat helps degrade the virus.

Nobody knows the temperature at which all the virus are dead in a fraction of a second, but in general higher T means shorter half-life. Get the half-life down to a minute or two, and you're home clear in 30 minutes. Think of a virion as a little bundle of chemicals that have to be all intact and in the right shape to work. And they're not just real stable. At room temperature they gradually break or deform. At higher temperatures, it's faster.

Refrigeration extends the viability of a virus sample. Heat increases it. I want something sterilized, I leave it in the car in the sun. Does it for sure hit the drop-dead temperature? No. But it's a lot hotter in the car and the virions degrade more quickly.

Don't do this with food. Of course. But it's a pretty safe bet it's okay for things like face masks, even if you reuse them in an hour.