BERLIN -- Orangutans at a Vienna zoo got buckets of water, lemurs in Rome enjoyed fruit icicles and a polar bear took to a pool in Germany as much of Europe sweltered Tuesday in an early summer heat wave.
Authorities warned that temperatures could top 40 degrees Celsius (104 Fahrenheit) in some parts of the continent over the coming days, the effect of hot air moving northward from Africa.
French Health Minister Agnes Buzyn said more than half of France is on alert for high temperatures Tuesday and the hot weather is expected to last until the end of the week.
"Heat waves are going to happen again, we know it, and maybe intensify in the next years and decades because of the climate change," she told reporters following the government's weekly Cabinet meeting.
France is still haunted by the experience of a 2003 heat wave that killed an estimated 15,000 elderly in the country. The government has since put in place numerous prevention measures including having local city halls contact fragile people and possibly visit them to make sure they're coping.
Meanwhile, public service announcements on TV and in the Metro urged people to drink water and keep an eye out for isolated older neighbors.
The message was echoed by the Red Cross federation's regional health coordinator for Europe.
"The coming days will be challenging for a lot of people, but especially older people, young children, and people with underlying illnesses or limited mobility," said Dr. Davron Mukhamadiev.
"Our message this week is simple: look after yourself, your family and your neighbors," he said. "A phone call or a knock on the door could save a life."
Paris Mayor Anne Hidalgo predicted heat waves like the one now sizzling Paris, expected to last about a week, "could last one, two, three months" if global warming continues unchecked.
Mobile teams are on the streets to provide water to the homeless. In the northern French city of Calais, regional authorities have provided 1,000 drums of water for migrants gathered there.
Authorities in 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.
Germany's meteorological agency DWD said it's possible the current June record of 38.5 C (101.3 F) could be topped on Wednesday. Helicopters were deployed to battle wildfires in the country's eastern state of Brandenburg, where forests have seen little rain lately.
In neighboring Czech Republic, the Hydro-meteorological Institute said temperatures might reach 37 Celsius (99 F) on Wednesday and warned the heat might damage train tracks.
At Schoenbrunn zoo in Vienna, keeper Fredi Maier said staff members were trying hard to provide some heat relief to orangutan trio Vladimir, Sol and Mota.
"The best way to do this is with water," he said. "Here they get water buckets but also hoses with holes in them so the water sprays like a garden hose. And they're loving it."
Sylvie Corbet and Elaine Ganley in Paris, and Karel Janicek in Prague contributed to this report.