LOWER FREDERICK, Pa. -- A 23-year-old man with cerebral palsy was found dead inside a van Monday evening in Lower Frederick in Montgomery County.

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Video: Man Left In Van Dies

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Police believe Nathan Krause's death was heat-related, but they are still investigating.

Police said Krause's death appeared to be a tragic accident, a miscommunication between family members after he was helped into the van at 8 a.m. and his mother and daughter each thought the other one was going to take him to camp.

Krause was found dead in the van around 4:30 p.m. His death was called an accident. No charges have been filed.

If heat is determined to be a factor in the death, it will be the second heat-related death in the area during this hot spell.

The Philadelphia medical examiner determined Joyce Dorsey, 60, died of heat stress complicated by lung disease. She was found inside her northeast Philadelphia home Sunday. The house had no air conditioning or fans and the windows were closed.

Joan Bland, with the Philadelphia Corp. For Aging, said the best advice was to drink water -- at least eight 8-ounce glasses per day. For senior citizens who don't have air conditioning, Bland suggested using SEPTA.