I manage a team and have a few members in my team who live alone and no other family in this country. One of them messaged yesterday to say she has been very unwell and has not gotten out of bed in 24hrs and so taking time off sick. I sent her a check in wattsapp this morning but she has not seen the message. At what point do you start worrying about them and what would you do in this situation? This happened once before with the other team member and I was equally concerned. I don't want to be intrusive but I also care for them.