Pro tempore can refer to either a judge or attorney who stands in a case instead of a different judge or attorney who was trying or defending the case until that point. This is usually done in emergency circumstances. The basis of this term is that the person standing in for the other is doing so on a temporary basis only.
The head of a government body who has to step aside for a set period of time for health reason or even for holidays will appoint a person to stand in their absence within that role, such a temporary person is referred to as a pro tempore.The temporary worker is taken from a lower rank than the standing judge or solicitor; in this way it is not uncommon for civil court cases to be heard by a pro tempore judge who actually holds credentials as an attorney and not a judge or a judge from a lower court.