Your psychologist deserves their own life to lead and we must keep this in mind. However, with that said they still have some responsibilities they owe their clients. This includes providing an emergency plan of action while they are away. Some people are lucky enough that their therapist will make themselves available by other means; but, the usual norm is to ensure that there is another means of help in any emergency. Again, if you are fortunate this means they will have another therapist on call. However, it seems many are simply referring their clients to the hospital emergency room. I would check with your therapist and their clinic office, if they have one, to confirm just what plan they have and stick to.