I agree that based on what we know so far, the risk of reinfection in the immediate future seems low. That's why I wrote a few pages ago that someone who was recently infected "probably" has immunity.
But what to do in the summer? I think that mask wearing should be more prevalent that it apparently is in the NY/NJ communities, based on what people are saying here. But certainly if someone finds that mask-wearing makes them overheated to the point of fainting in the street, they may not be able to wear it.
I don't know where one draws the boundary between safek pikuach nefesh and a part of living life. We do cross streets, but only after looking both ways. We do operate a vehicle, but only after fastening the seat belts. I think masks belong in the same category - a safety feature that we hope will be unnecessary, but we use, just in case.
First of all, if the risk of an immediate reinfection without any mask, is very low, why would it be different than driving a car with a seatbelt. Even with a seat belt, there is a possibility of mortal injury.
Second, why do you say "if someone finds that mask-wearing makes them overheated to the point of fainting in the street, they may not be able to wear it." Even if it's just causing a discomfort, it is not reasonable to expect for a far-fetched risk.