Zookeepers in the Swiss financial center of Zurich are feeding animals a diet of frozen berries, meat and bones to help them stay cool in the sweltering summer heat.

The "alternative ice cream" offered to animals instead of their usual fare has been a big hit with large cats, apes and wolves, Zurich Zoo said in a statement. "The ice cream should at least offer the animals a temporary way to cool down," it said.

The unusually high temperatures which have hit most of Europe are poised to make this July the hottest in Switzerland since 1983, experts say.