It’s super nice outside with mild temperatures, low humidity, and trees and blooms bursting to life. It’s tempting to take Fido along for a ride. But it can be surprisingly dangerous to leave your pet in the car, and few of us realize how quickly temperatures inside can reach life-threatening levels.

According to the Partnership for Animal Welfare (PAW), a car parked in the shade on a 78-degree day can reach 90 degrees inside. Parked in the sun, the interior of that car will soar to 160 degrees! And because dogs and cats don’t sweat and are forced to pant, inhaling that overheated air, just 15 minutes is enough to leave your beloved pet with nervous-system damage or comatose.

Leaving the windows down doesn’t help that much, says PAW, and leaves your pet vulnerable to being stolen and you liable if your animal bites someone who reaches through the window (it happens). And while leaving the car running with the air conditioning on might seem like a reasonable solution, several animals, including a Texas police dog, have been killed when engines overheated and their AC systems began pumping the vehicles with hot air.

Maryland is one of the few states where it’s illegal to leave your pet in a car “in a manner that endangers or safety of the cat or dog.”

The best idea, experts say, is to leave your animal at home when temperatures are above 70 degrees or below 40 degrees (freezing to death is not a nice way to go, either). If you’re on your way to a destination where your pet is also invited, take along plenty of fresh water for your furry friend. And be aware of signs of heat exhaustion, including excessive thirst, heavy panting, lethargy, glazed eyes, vomiting, lack of coordination, or an unusually dark tongue. A dog or cat exhibiting those symptoms should be taken to the vet immediately, while you offer water to drink and place a cold towels or ice packs on his or her head, neck, and chest.

If you see an animal suffering in a hot car, call 911 immediately.

You and your pet can have a great spring and summer with a little common sense. Bring on the fun!