How zoos in the hottest parts of the country keep animals healthy during extreme heat

Animals are perhaps more readily equipped than humans to deal with extreme heat. But when the heat index climbs into the triple digits, accredited zoos in the hottest parts of the country are still tasked with ensuring that animals – and their human counterparts who come to visit – are staying safe in the scorching temperatures.

The Association of Zoo and Aquariums sets species-related heat guidelines for facilities to follow once temperatures begin to rise.

"We definitely need to monitor all of them to make sure that they are thermal regulating appropriately and that they're comfortable, especially in the hot summer months," Kelly Trotto, associate curator of behavioral husbandry at Florida's ZooTampa, told ABC News.

One of the main components of zoo heat safety is housing primarily those animals that have adapted to regularly occurring extreme heat in their natural environments, zookeepers told ABC News.

In Palm Desert, California, for example, visitors will find only hot-adapted species at the local zoo, Tim Van Loan, an animal behavior specialist at The Living Desert Zoo and Gardens, told ABC News.

"It can get scorching here, and so the best thing for us is to have animals that are already adapted to this kind of environment," Van Loan said. "... It gets hotter than, you know, anyone would be comfortable with."

Likewise, there are no polar bears to be found at the Phoenix Zoo, a facility that's no stranger to long stretches of triple-digit temperatures, Bert Castro, president and CEO of the Arizona Zoological Society and Phoenix Zoo, told ABC News.

The Phoenix Zoo features animals that are native to the Southwest U.S., as well as species from Africa, the Middle East, tropical Asia, and tropical South America.

Most of the animals at ZooTampa are native to climates that are warm and humid, as are the animals at the Houston Zoo in Texas, including species ranging from large cats to small primates, zoo officials told ABC News.

Even so, animals are often given multiple options to stay cool within their enclosures.

Zookeepers at The Living Desert offer the animals natural choices that they would find in the wild, Van Loan said. These include trees and bushes that the animals can use for shade, water features in which they can cool off, and wallows – a depression in the ground filled with mud – in which they can do the same.

On hot days, the rhinos can be seen swimming with pelicans within their pond, while the desert animals tend to burrow into the ground, Van Loan said.

"Within each of our habitats, which are all naturalistic, we offer different kinds of choices that allow the animals to kind of choose on their own where the best place to cool off is," he added.

Enclosures at ZooTampa are also designed with features that allow animals to seek relief in ways similar to how they would in the wild, Trotto said, noting that the zoo's black bear especially loves to spend time in the water.

Zookeepers at the Phoenix Zoo will give many of the animals daily baths to help keep them cool, Castro said. Mud baths are also popular at The Living Desert, Van Loan said.

At the Houston Zoo, the preference is often water misters, Denny Charlton, the zoo's supervisor of carnivores, told ABC News. The carnivores tend to sleep for much of the day during the summer, he said, noting that "The tiger likes to lay in the shade behind the bamboo."

Ice treats, consisting of the animals' daily diet items frozen into ice, are offered on very hot days. "Blood-cicles" are especially popular among the carnivores, while "fish-cicles" are given to animals with aquatic diets, the experts said.

Sometimes the treats will be hidden in trees or elsewhere. Recently, the ZooTampa black bear was given pieces of watermelon frozen in a five-gallon bucket.

"What that did was offer her a way to cool down but also offer her an opportunity to forage, which is something that black bears do all the time," Trotto said.

Some of the animals at The Living Desert will even hug the large pieces of ice treats given to them to cool down, according to Van Loan.

"It's pretty adorable," he said.

For older animals or species that may be more susceptible to heat, however, many zoos have enclosures equipped with air conditioning. For Phoenix Zoo animals that don't have access to an actual building, water coolers nears their exhibits have been installed to blow cool air, Castro said.

Recently, the Phoenix Zoo introduced an Amur leopard, a cold-weather, critically endangered leopard species native to southeastern Russia and northern China. The air conditioning for Jasper, a 4-year-old Amur leopard born in 2020 at South Carolina's Greenville Zoo, blows "super strong," Castro said.

"We do everything we possibly can to ensure that our animals are healthy, comfortable, especially during these really hot times during the summer," he added.

Keepers are trained to monitor zoo animals for signs of heat stress, but the species that seems to fall victim to heat-related illness the most is humans, Castro said: "What we really see are the people that come out to the zoo who come out unprepared."

The facilities will often open in the early morning and close after lunch time, prior to the hottest part of the day, to lessen the chances of heat-related illness among guests.

During the summer months, the Phoenix Zoo opens as early as 6 a.m. for members and closes at 1:30 p.m., while The Living Desert also closes at 1:30 p.m. Security officers at the Phoenix Zoo also monitor visitors for signs of heat stress and carry water and electrolyte packets to hand out as needed.

However, it's not only typically hot regions that are having to deal with increased temperatures. As global temperatures continue to increase due to human-caused climate change, regions in historically frigid climates are increasingly experiencing record-high temperatures as well.

The Alaska Zoo in Anchorage is among the cities seeing changes in weather patterns, Katie Larson, communications manager for the Alaska Zoo, told ABC News. That includes more erratic winter weather as well as less variable summer temperature.

Once temperatures started to approach 80 degrees, Alaska Zoo personnel make sure to check on the animals more frequently and ensure they have plenty of water, Larson said. The animals also will seek shade and a comfortable place to lie down.

"The animals that are at the zoo are cold climate species," she said. "We really don't do heat super, super well."

What's more, should temperatures climb even higher, the zoo is not equipped with air conditioning to ease the heat stress, Larson said.