PENNDEL (AP) — A toddler who was accidentally left in a hot minivan outside his suburban Philadelphia day care center has died of hyperthermia.

Authorities in Bucks County say 2-year-old Daniel Slutsky was left in a locked vehicle with the windows up for more than six hours on Wednesday.

County coroner Joseph Campbell says Slutsky had been driven to the Penndel day care center by a neighbor who operates the facility. Campbell says Rimma Shvartsman forgot about the toddler and returned to the car around 4:45 p.m. to find him unresponsive. Shvartsman's lawyer, Michael Mustokoff, says the death is a "tragic accident" and that his client is cooperating with the investigation.

Temperatures were in the low 80s on Wednesday. Campbell ruled the boy's death an accident.

District Attorney Michelle Henry says no charges have been filed and the investigation is continuing.