Does the volunteer who takes the temperature of worshippers at the mosque entrance receive the reward for congregational prayer if he prays individually after it has finished, and is he sinful for not praying with the congregation?

A Muslim is commanded to pray in congregation as long as he hears the call to prayer and it is not difficult for him to go. Among the excuses that permit abandoning congregational prayer is being preoccupied with taking the temperature of worshipers, if there is an overriding benefit in it, such as when the responsible authorities have obligated the mosque's people to do this, or when the disease is widespread and this measure serves to preserve lives. This matter takes precedence over preserving wealth. However, if there is no overriding benefit, such as when official authorities have not mandated this, or when the disease is not widespread, then taking the temperature is not an excuse to abandon congregational prayer.