To combat the persistent heat wave in Zurich, animals in the zoo are fed a diet of frozen berries, meat and bones to help them stay cool.

The "alternative ice cream" offered to animals instead of their usual diet has proved successful with large cats, apes and wolves, reports Reuters news agency.

"The ice cream should at least offer the animals a temporary way to cool down," Zurich Zoo said in a statement.

The high temperatures in most of Europe are primed to make this July the hottest in Switzerland since 1983, experts say.