Police charged a Kentucky father with criminal abuse after he allegedly failed to protect his shirtless, fair-skinned 2-year-old from the sun before leaving the child out to play in 95-degree heat for more than an hour.
The boy suffered second-degree burns, police said.
"It was downright brutal down here, we had 90 degree temperatures all day," Berea Police captain Ken Clark told ABC News on Tuesday.
"The father has said the child was just out playing, but we felt we established probable cause to charge him with a crime; when you talk about a 2-year-old child, someone who cannot speak up for themselves, in that type of heat ... There must be someone responsible for his safety."
Second-degree burns are extremely red and blistered -- and very painful.
Authorities allege that Bobby Jones, 27, did not take adequate care to ensure his son's safety.
Jones, who was unable to post bail, was still in jail and unavailable for comment Tuesday evening. The child's mother could not be reached.
But Jones' mother, Joanie Lee Spivey of Sandgap, Ky, said that her son could not have intentionally hurt the child.
"He's a good man and a good daddy, anybody can tell you that," she said. "He bought the baby a swimming pool, and they was just playing in the water. I didn't think that was no harm, but he wouldn't hurt that baby; no way."
The incident reportedly occurred in the early afternoon, when police allege that Jones left the child outside with no sun repellant of any kind.
Initial reports say the child was treated immediately at Pattie A. Clay Regional Medical Center in Richmond, Ky., after his mother picked the child up from Jones, only to discover her son severely burned.
Spivey believes her son was not at fault for the child's severe burns and disputes the severity of the sunburn.
"He ain't burned that much bad," she said. "It was just a little red that day."
Medical records from the Pattie A. Clay facility were unavailable. But police captain Clark said the burns were significant, especially for a two-year old child.
"The burns covered the tops of both of his shoulders, they had blistered and then on one of his shoulders those blisters had broken. So we're talking about pretty substantial burns to a large area," Clark said.
Clark said he believed the man had acted negligently, but added it was understandable that severe sunburn instances sometimes occur.
"I've seen children with sunburn, and that's going to happen," he said. "Even we as adults go to sleep when we shouldn't and wake up crispy critters. But it saddens me to see any child have to suffer through something like this. This hasn't been adjudicated yet, so we can't dispute anything or say one way or the other. But we established our cause and now the court will do what it will."
ABC News' Gerard Middleton contributed to this story.