A police dog died Monday in Houston after being left in a patrol car without air conditioning, the second heat death of a police dog around the United States this month.

The dog, a 4-year-old named Aron, had been working with the Houston Police Department for a year and a half. The department released a statement on Twitter Tuesday announcing that Aron died from heat exhaustion.

Aron’s handler left him in the car when it was running and had air conditioning on, “which is a necessary and common practice when the K-9 partner is not actively engaged in police work,” according to the statement. However, upon returning to the patrol car, Aron’s handler found the dog in distress inside the car, which was off. The dog was then taken to an emergency vet where he died from the heat.