"We can't save human lives by not forcing them to come into work at the threat of firing and loss of livelihood because we might accidentally save a life that wasn't in danger if we let employees make that risk assessment for themselves by giving them the option to choose."

As far as the manager knows its none of their fucking business because the employee should be the one who makes that call about their personal safety, not their manager, and said employee can't freely make that call if they face reprisal or loss of promotion for doing so.