When they return from a call out they may have dealt with something relatively straightforward (e.g. someone a theft) or attended something potentially traumatic, like a fatal road traffic collision. It is helpful to remember this because they may return to work in different mindset to when they left an hour ago.
It is your employee’s responsibility to make sure they’re physically and mentally fit to return to their workplace and they will become adept at managing this transition. However, we recommend you talk to them about how you and they can best deal with this and then let other workmates know. They might appreciate a cuppa and a quick “You OK?” but are unlikely to want (or be able) to discuss the incident they’ve attended. Take your lead from them.
It is normal for people to be a bit preoccupied after they’ve attended an upsetting job so don’t be surprised if they’re a bit quieter for a few days, or perhaps a week or two. You can understand more about reactions to trauma and stress
on this website.
If you’re worried about them, ask how they are. It may or may not be something to do with their responder role, but they will appreciate you asking. Have a look at the advice on the Good management and Leadership