Check up on each other, and make time to ask someone face to face if they are really OK? Body language is a good indicator of how someone is coping. If they are showing signs of being under pressure, just a kind word can often open the channels for discussion.
Too often, we just casually ask “Are you OK?” We are only being friendly but we are unlikely to get an honest response. We should bring back the Stop, Look, Listen previously used to cross the road and apply to our friends and colleagues.