VIENNA (AP) — Orangutans at Vienna's Schoenbrunn zoo are keeping cool with buckets of water as much of Europe swelters in a summer heat wave.

Keepers gave Vladimir, Sol and Mota wet sponges, water hoses and a large tub to frolic about with as temperatures pushed 32 C (almost 90 F) in the Austrian capital Tuesday.

Authorities in neighboring Switzerland raised the heat warning to the second-highest level for areas along the southern and northern borders with Italy and Germany, warning people to avoid strenuous activity and stay hydrated.

Firefighters are using helicopters to battle blazes in Germany's eastern state of Brandenburg, where forests have seen little rain lately.

The peak of the heat wave, caused by warm air streaming northward from Africa, is expected toward the end of the week.