A West Yorkshire council says it is "desperately" short of people to provide short-term care for children with disabilities.
Kirklees Council says it has just two dedicated short-break carers who can take over round-the-clock care duties from parents.
The council said it was now "urgently" calling for about 20 new volunteers.
It said a lack of foster carers, who can also act as short-break carers, had sparked the appeal.
John Heron, Kirklees Council's carer recruitment manager, said short-break care was an "invaluable" service for the parents of children with disabilities.
"Caring for a child 24 hours a day, seven days a week can be extremely challenging," he said.
"It is important that they are given the opportunity to recharge their batteries, catch up on lost sleep, spend time with other children or go away on holiday."
Kirklees Council's two dedicated short-break carers work with about 10 families in the district.
Judi Gibbons, a short-break children's carer in Kirklees for the past 22 years, said it was "the best job in the world".
"The rewards make it all worthwhile. It's an amazing feeling to see a child smile and know that you have made a difference," she said.
Kate Seabridge, whose 11-year-old son, Archie, stays with Mrs Gibbons for three days a month, said getting a break from being a carer was "a real lifeline".
"Being able to go on bike rides or long walks means you can do things that make you feel like a normal family," she said.
Kirklees Council said successful volunteers would be given training, and would receive payment based on the number of days of care they gave each month.