It has been known for respite carers to eventually be asked by a family to adopt their child. Some respite carers will have had special training to care for the needs of very handicapped or challenging children. This kind of foster care can be very suitable for people who need to know that a placement will be very short (but repeated at more or less regular intervals), because respite care will almost never be longer than a couple of weeks, and is very often measured in hours or days. Respite care is often a critical component of family preservation efforts.