Warm summer weather means lazy days on the river, outdoor adventures and taking furry friends along for the ride.

By the same token, it also means hot cars and potential danger for pets if they aren’t allowed inside an establishment.

Temperatures inside a car can increase by 19 degrees in as little as 10 minutes, according to data from San Francisco State University. It can rise by 43 degrees in one hour.

“At 70 degrees on a sunny day, after a half hour, the temperature inside a car is 104 degrees. After an hour, it can reach 113 degrees,” informational site HeatKills.org states.

Cracking the windows does help slightly, but it’s not enough of a difference to lessen the danger. The vehicle is still enclosed enough to hold onto heat.

Sadly, many pet owners make the fatal mistake of leaving their pets in the car for “just a few minutes.” It doesn’t seem harmful, but every single minute counts when it comes to a car in warm weather.

Imagine an 80-degree day in a parked car. Even with the windows cracked, most people begin sweating after a minute or two, and by 10 minutes, they have to turn on the air conditioning. That is with bare skin that perspires.

Now, consider a dog covered in fur whose body can only cool off through panting. The danger is clear.

It is never OK to leave a pet in the car at all on a warm day — but certainly not more than two minutes. Doing so is irresponsible and doing a gross injustice to man’s best friend.

Consider leaving Fido at home if errands are on the agenda. Don’t bring a furry friend along if plans involve eating at a restaurant, going shopping or even making a pit stop at the grocery store. Leaving a pet at home is always better than having that pet succumb to overheating.

Your best friend will thank you for it.