Expert: Death by hyperthermia in cold very rare
A study of 231 pediatric deaths by hyperthermia, or overheating, in vehicles between 1999 and 2007 showed nine children died after exposure to heat for 30 minutes or less, longtime Mesa County forensic pathologist Dr. Robert Kurtzman told jurors Tuesday in Heather Jensen’s trial.
Qualified by District Judge Valerie Robison as an expert witness, Kurtzman told the nine-woman, five-man jury that literature he’s researched says children have died after exposure of as little as 15 minutes.
“How many of those deaths happened in the winter?” Public Defender Thea Reiff asked on cross-examination.
“None,” Kurtzman replied.
The death investigation for brothers William Jensen, 2, and Tyler Jensen, 4, revealed “very unusual, extraordinary” circumstances, Kurtzman testified. The brothers are among just six documented pediatric hyperthermia deaths, in a vehicle, occurring in the United States during the wintertime.
“Fair to say there are a lot more cases when children are taken to a hospital and survive?” Assistant District Attorney Rich Tuttle asked.
“Yes,” Kurtzman said.
The defense has argued risk of death by overheating in late November, in 30-degree weather, wouldn’t have registered with someone like Jensen, who was said by her own lawyer during opening statements to be “bordering on developmentally disabled.”
Prosecutors have said Jensen, 25, failed to perceive a substantial risk and was criminally negligent in the Nov. 27, 2012, deaths of her boys on Grand Mesa inside Jensen’s Toyota 4Runner.
Kurtzman’s anticipated testimony Tuesday capped the District Attorney’s case after four days of witnesses. The jury will learn this morning if Jensen — who was advised Tuesday by the judge on her rights on the issue — will testify or if they’ll hear from other possible defense witnesses.
Jensen is seen on video-recorded interview with law enforcement acknowledging she’d turned on the 4Runner’s heater, but not hot enough, “to, like, roast or anything.” After being confronted about time frames, she eventually acknowledged the boys could have been alone up to 90 minutes.
Kurtzman ruled William and Tyler died from hyperthermia.
Kurtzman also ruled the deaths were an “accident,” and not homicide, and observed the deaths were a result of Jensen’s “neglect.” Those findings, however, weren’t given to the jury after Robison ruled the information off-limits for fear of causing confusion.
Asked on Tuesday how long the Jensen boys — per testimony, wearing jeans, long-sleeve shirts and socks — could have survived with temperatures around 130 inside the 4Runner, Kurtzman responded, “relatively short.”
“We’re not talking about four, five, six hours,” he said.
Testing completed at Powderhorn aimed at recreating conditions in Jensen’s 4Runner showed temperatures hitting 132 degrees, or higher, within 45 minutes.
Kurtzman testified the boys couldn’t have slept through such temperatures because children become irritable. For adults working in conditions of 110 degrees or more, the Occupation Safety and Health Administration recommends rehydration to the tune of more than a gallon of water after heavy exertion, and 15 minutes of rest for every 45 minutes worked, Kurtzman testified.
Children, however, are at greater risk from hyperthermia, and would show symptoms faster, because of physical characteristics including sweat glands not being fully developed. That makes it harder for the body to naturally cool down, Kurtzman said. It’s compounded when a child is strapped in a car seat and skin surfaces are covered, preventing perspiration, he said.
“If you have someone secured into an object, that diminishes an opportunity to lose heat (from the body),” Kurtzman said.
Autopsies on William and Tyler showed evidence of burst blood vessels on their lungs, a product of increased gasping for breath. Losing body moisture, with the heart pumping faster, the boys would have been panting in a desperate effort to relieve the heat, Kurtzman said.
Jensen is charged with two counts of criminally negligent homicide, two counts of child abuse resulting in death with negligence, and false reporting.
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