Police identified the child on Thursday as 3-month-old Jamison Gray. Jamison's father, 31-year-old Daniel Bryant Gray, went to B.T's Sports Pub where he works as a kitchen manager at about noon on Wednesday and left his son in the car when he went inside.
Police spokesman Tommy Thompson said during the course of their investigation, detectives learned Bryant was smoking marijuana with a co-worker while his son was left in the vehicle.
Temperatures in Phoenix were about 100 degrees at the time, but car interior temperatures soar once the air conditioning is turned off.
Thompson said Bryant was booked into Maricopa County Jail Thursday night.