I believe you should pause and assess for hazards before entering the room.
You shouldn't rush and get yourself in danger too, but you should rather think about your options and see if there is any imminent danger. Then, when you assess the situation, you should enter the room and try to help your coworker if he is in trouble. You shouldn't wait for someone to come and help you because it might be too late then, but you should definitely assess the situation first.
