In the wake of the deaths of numerous K-9 dogs who were left in hot police patrol cars this summer, PETA has sent a letter to more than 50 police associations urging them to encourage their members to install temperature-monitoring and heat-alert systems in K-9 units.

Such systems sound an alarm, page an officer, attempt to start an engine, roll down a window, or pop a door open if the temperature begins to reach a dangerous level.

In its letter, PETA cites several examples of K-9 deaths in 2012 alone, including two Bexar County, Texas, K-9s who perished after being left in their kennels in a K-9 truck for more than a day while temperatures outside reached 96 degrees—just two years after another K-9 belonging to the same department died en route to a veterinary clinic after being left in a hot patrol car.

"Police departments across the country are proud to serve and protect, and that mission must include their dutiful K-9 partners," says Martin Mersereau, PETA's director. "Taking a few simple steps to monitor police dogs in patrol cars can mean the difference between life and an agonizing death from heatstroke."

Hot weather is often deadly for dogs, who can succumb to heatstroke in just 15 minutes and sustain brain damage as a result. Dogs who are left in parked cars are especially susceptible. Dogs locked in hot vehicles have been known to salivate heavily, lose control of their bladder and bowels, and claw car windows so violently that their paws become bloodied.

On a 78-degree day, the temperature inside a shaded car is 90 degrees, and the inside of a car parked in the sun can reach 160 degrees in minutes. Symptoms of heatstroke include restlessness, excessive thirst, heavy panting, lethargy, lack of appetite, a dark tongue, vomiting, and lack of coordination.