(DALLAS) -- Former NFL player Marion Barber III died from a heat stroke in his suburban Dallas apartment amid a record-setting heat wave sweeping across Texas, according to the Collin County medical examiner's office.
The 38-year-old's death was ruled an accident, the medical examiner said Monday.
Barber, a former running back for the Dallas Cowboys, was found dead in his Frisco, Texas, apartment on June 1 after police were requested to conduct a welfare check on him, according to the Frisco Police Department.
The former Pro Bowl player's death came at the start of a heat wave in the Dallas area and across Texas that has seen temperatures soar into triple digits, taxing the state's electrical grid and prompting the Electric Reliability Council of Texas to issue a statewide appeal on Monday for people to conserve energy.
Records from the National Weather Service show that during the week Barber's body was discovered, daily high temperatures in Frisco ranged from the high 80s to the low 90s.
A full autopsy report on Barber obtained by the Fort Worth Star-Telegram shows that when police officers arrived at Barber's rented apartment to check on him, the thermostat was set to 91 degrees with the heat set to "on."
"Mr. Barber was known to exercise in sauna-like conditions," the medical examiner wrote in the report, according to the Star-Telegram.
Frisco police said Barber's family members had not heard from him for six days before the day his body was discovered.
Barber's father, Marion Barber II, also a former NFL player, told the Star-Telegram his son's body was badly decomposed when officers found him.
A police incident report, obtained by ABC affiliate station WFAA in Dallas, said police were contacted by an employee at Barber's apartment complex on June 1, who expressed concern for Barber's well-being.
The employee told police a neighbor submitted a service request on May 11 due to water leaking into their apartment from Barber's unit, according to the incident report. The employee said he was unable to contact Barber on either May 12 or 13, and added that numerous phone calls and emails to Barber were not answered for two weeks. Police officers found an unopened letter the employee left on Barber's door when they arrived at the apartment on June 1, according to the incident report.
Officers found Barber's body in a bathroom shower with the water not running, according to the incident report.
Heat stroke occurs when the body can no longer control its temperature, causing a person's body temperature to rise rapidly and its sweating mechanism to fail, making the body unable to cool down, according to the Centers for Disease Control and Prevention. During a heat stroke, a person's body temperature can rise to 106 degrees in 10 to 15 minutes, according to the CDC.
Besides an extremely high body temperature, warning signs of heat stroke include a rapid pulse, throbbing headache, dizziness, nausea, confusion and red, hot and dry skin, according to the CDC.
Barber, a standout three-sport athlete at the University of Minnesota, was picked by the Dallas Cowboys in the fourth round of the 2005 NFL draft and played for the team for six seasons, earning a Pro-Bowl selection in 2007. Barber signed with the Chicago Bears in 2011 and played one season for the team before retiring in 2012.
"We are heartbroken by the tragic death of Marion Barber III. Marion was an old-school, hard-nosed football player who ran with the will to win every down," the Cowboys said in the statement when Barber's death was first announced. "He had a passion for the game and love for his coaches and teammates."
A funeral for Barber was held on June 22 at the Huntington Bank Stadium on the campus of the University of Minnesota.