Guardianship is a form of custody of a child awarded to non parents, by either the probate court or the juvenile court (sometimes a family court)temporary custody is an order made pending trial.
The answers on this discussion board are general in nature and NOT intended as legal advice. Responding to questions does not constitute an attorney-client relationship. Always see a lawyer about your individual situation.
I assume that the Juvenile Court is not involved since you sound like you are interested in voluntarily giving custody to a relative. This could be done by filing a Probate Court Guardianship Petition. However, you should speak to an attorney first to understand whether this is best for your child or whether an alternative such as a Caregivers Affidavit Authorization may be appropriate.