This guy was lucky enough to stay at a camp site in Zambia on the edge of South Luangwa National Park. They had a swimming pool with shallow sloping sides all the way around rather than vertical sides and a ladder.
It was because hippos would also sometimes stray from their pod and get into their pool to cool off. If they sides weren’t a shallow enough slope then they’d get stuck and the owners would have to arrange for the hippo to be tranquillised and removed by crane.
Apparently a while back a hippo had wandered into the camp site covered in large wounds which appeared to have been inflicted by lions. It got into the pool to recover and cool off and stayed for 3 days. They had to drain the pool and wait for the hippo to get too hot and leave by itself to cool off in the river.