A helpless Florida man with Down syndrome died in the back of a 125-degree car when his caregiver fell asleep for hours after taking recreational drugs, according to authorities.

John LaPointe, a 35-year-old who could not talk or care for himself, was unable to rouse carer Joshua Russell, 26, as he slept in the driver’s seat for up to three hours, Pinellas County Sheriff Bob Gualtieri said.

“Let’s just call it what it is — this poor guy baked in that car,” Gualtieri said at a press conference Friday.

“It had to be absolutely horrific in that car for that man.

“He was sitting in there and the van got extremely hot, there was nothing he could do. He couldn’t do anything to help himself.”

Authorities revealed full details of the horrible death in Seminole in May after Russell was arrested Friday following a lengthy investigation and charged with aggravated manslaughter of a disabled adult.

He had been taking LaPointe, who had the cognitive ability of a 1-year-old, for a doctor’s visit when he decided to take a detour home to dose himself with the opiate-like plant Kratom, the sheriff said.

Russell took the plant, which is not a controlled substance, as a recreational drug to help him “feel awake and alert,” Gualtieri said, but instead took so much, he ended up passing out in the Toyota minivan.

When he awoke hours later, he “saw Mr. LaPointe slumped over in his seat and not breathing,” the sheriff said at the press conference, noting that CPR could not save him.

Officials were unsure how Russell survived the heat, which tests later showed would have been 125 degrees.

Feeling suicidal, Russell went back inside his house to get a gun “because he was going to kill himself,” the sheriff said, before his mother talked him out of it when he phoned her to say goodbye.

Russell was charged at the time with carrying a concealed firearm before being hit with the aggravated manslaughter charge Friday.

He was released on a $50,000 bond, according to Bay News 9.

Gualtieri said the case highlighted fears of people abusing legal substances that can still have strong, drug-like effects.

“Just because these products are legal … it doesn’t eliminate the obligation to do it in a responsible way,” he said.