Going into the first 90-degree days of the summer, the Denver Department of Public Health and Environment advised pet owners to keep them indoors and out of parked vehicles.

Dogs are especially susceptible to the scorching summer heat because they don’t sweat like humans do.

While humans cool their bodies through sweat, dogs release heat through panting — they breathe in cold air and release hot air with each inhalation and exhalation, the health department noted in its news release.

But if the temperatures are too high outside, dogs do not have any cool air to breathe.

Leaving a dog inside a vehicle is particularly dangerous because even on an 80-degree day, vehicles can reach 109 degrees after just 20 minutes of sitting in the heat, according to the U.S. Centers for Disease Control and Prevention.

So far this year, Denver Animal Protection reported receiving 130 calls for animals confined in vehicles during extreme temperatures. The unit received 450 calls in 2023.

When owners leave dogs and other animals outside for too long in the summer heat, they can easily overheat and suffer organ failure – or even death.

Exposing a pet to the extreme heat can also result in fines up to $999 and 300 days in jail, according to Denver Animal Protection.

The unit urged the public to call the Denver Animal Protection dispatch at 720-913-2080 if people see a pet left outside or in a locked vehicle.

Officials also noted that Denver’s Good Samaritan law offers legal immunity to anyone who breaks a car window to save an animal under certain circumstances, such as making a reasonable effort to find the owner, checking to see if the vehicle is locked and believing that the animal is in immediate danger.

Before taking a pet on a trip to the park or possibly for a run outside, the department offers the following guidelines:

• Keep the time outdoors to a minimum

• Have water readily available

• Lead pets away from hot pavement

• Consider investing in boots or sunscreen specially designed for animals

“Remember,” said Tammy Vigil with Denver Animal Protection in the news release, “if you love ‘em, leave ‘em … at home. It’s the most protective place for your pet during the hot summer months.”