"The longer I waited, the more I was thinking about this moral dilemma to myself, the more the answer became obvious to me because the dog was in clear distress," he said.
Finally, Klonis said he couldn't wait any longer. He asked his girlfriend to record him on cellphone video and, using a crowbar, shattered the car's window.
The couple then removed the dog from the car and gave it water.
Minutes later, the owner came out of the restaurant and police and animal welfare arrived at the scene. Klonis was worried he'd be in trouble for breaking the window, but Albuquerque police said it's legal to break into a car to rescue a child or dog, KOB-TV reported.
"It takes very little time for temperatures to get up to 120, 130 degrees inside that vehicle," Adam Ricci, of Albuquerque Animal Welfare, told KQURE-TV.
The dog's owner was cited for animal cruelty and could face up to a $500 fine and up to 90 days in jail.