No one is obligated to put themselves at risk but you can think of it as a choice that you can make to benefit others. All the doctors and nurses who have come

No one is obligated to put themselves at risk but you can think of it as a choice that you can make to benefit others. All the doctors and nurses who have come out of retirement to work in hospitals at a time where their personal risk is high are doing it not because they feel obligated but because they recognise it is something they can do now so that fewer people suffer in the future. Choosing to go to the grocery store even when there are lower risk alternatives should be the same.