The Canyon County coroner says Devon Nettleton, 10, of Middleton died from heat exposure.

CALDWELL -- Canyon County Coroner Vicki DeGeus-Morris has concluded that the death of a 10-year-old Middleton boy was a tragic accident.

Following an autopsy today, the coroner said it appears that Devon Nettleton died from heat exposure. His death has been ruled accidental.

There were no signs of trauma, bruises, or anything else on the body.

The boy's body was found around 8 a.m. Thursday in a remote, rural canyon near the Canyon-Gem County line. It was located 1.8 miles from where he had left a backpack and other personal items.

His uncle reported him missing around 2:30 p.m. Wednesday after the two had gone there to retrieve an ATV that had gotten stuck on Tuesday.

DeGeus-Morris said Nettleton had been outside exposed to the elements for around 17 hours and likely died from environmental hyperthermia. Temperatures in the Foothills south of Emmett that day reached into the mid-90s.

She believes the boy became disoriented and the heat was too much for him. Hyperthermia sets in when the body fails to adequately cool itself.

The time of death is estimated to be around 7 p.m. Wednesday, just 4.5 hours after he went missing.

The Canyon County Sheriff's Office does not anticipate any criminal charges in this case, saying the family is already going through enough dealing with Devon's death.

Meanwhile, the family has set up a memorial fund at the Syringa Bank in Middleton to help pay for Devon's funeral expenses.

Reporter Ysabel Bilbao contributed to this story.