Low risk of everything, but every time you’re rolling the dice on permanent lung damage. If they have any family history of things like athsma or sarcoidosis then that’s a lot more serious than it is for someone who doesn’t because those diseases can appear suddenly in adulthood. As for how much it sucks when you’re actually feverish that varies a lot person to person, I was sidelined for about four days but I have a friend who could barely move for two weeks. Obviously just because you’re not symptomatic doesn’t mean you’re not still infectious either.