The temperatures have risen, and with them, the perennial warnings: Don’t leave your dog in a hot car.

Brattleboro police are stressing that advice, urging dog owners to take responsibility and learn the risks. Many owners, police said in a news release, may not be aware of the range of situations that could put their dog in danger.

Most people know, for instance, that a closed, parked car can get hotter than outside temperatures. But they might not know just how hot — a 70-degree day outside can make the temperature inside the car 100 degrees, according to police. A 75-degree day raises that internal car temperature to 118 degrees, police said.

Cars heat up quickly, too. On a 70-degree day, a car can heat up to 89 degrees after 10 minutes, and 99 degrees after 20, according to a study by San Francisco State University. A car left for 10 minutes on an 85-degree day climbs to 104 degrees in 10 minutes, and 114 degrees in 20, the study says.

Animals can suffer heatstroke and die after just 15 minutes in a hot car, according to People for the Ethical Treatment of Animals.

In New Hampshire, leaving animals in hot cars is a misdemeanor offense under RSA 644:8-aa. And police officers or members of a licensed humane organization are not liable for breaking a window if necessary to rescue the animal.

Barry Hilton, animal control officer at the Keene Police Department — who says he’s often called out to check on dogs in hot cars — says dog owners are often unaware of how long they’ve left their dogs behind.

“Every (owner) says the dog was only in the car for five minutes,” he said. “But it took me over five minutes to get there after I first heard the call.”

Hilton also says that people might leave their dogs in cars with the windows cracked or in shady areas, not appreciating that this is still dangerous. The San Francisco State University study indicates that neither strategy has much effect on internal car temperatures.

Hilton’s advice? If it feels warm, don’t take the dog out at all.

“If you’re gonna go shopping, just leave your dogs at home,” he said.

Ethan DeWitt can be reached at 352-1234, extension 1439, or edewitt@keenesentinel.com. Follow him on Twitter at @EDeWittKS