A South Carolina couple was found dead over the weekend in their Spartanburg home, the interior of which registered a temperature of 120 degrees when they were discovered by authorities, according to local reports and the police.

The couple has been identified as 84-year-old Joan Littlejohn and 82-year-old Glennwood Fowler, The State reported, citing the coroner's office. 

Family told investigators they were at the home last Wednesday to check on a heater, after the couple complained about the house being too cold. 

Spartanburg police conducted a wellness check at the home after the family said they had not heard from the couple for three days. 

First responders entered the home through a bedroom window and found the couple dead. Their temperatures exceeded the thermometer's highest measurement of 106 degrees Farenheit, police said. 

Spartanburg fire official Brad Hall told McClatchy News that the home's temperature was measured at 120 degrees. 

Firefighters entered the basement where the heater was kept to determine why the home was so hot. Using thermal imaging cameras, fire officials determined the heater was about 1,000 degrees. 

Fire officials disconnected the heater and a paramedic contacted the county coroner's office. 

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Coroner Rusty Clevenger ruled out foul play in his Jan. 8 report, but noted that officials were "concerned with why the temperature was so high." 

"We followed through with forensic exams this morning that will require more testing," he said. "CO2 is one test as it was mentioned in the police report. We will continue to investigate," he said. 

A spokesperson from the Spartanburg Police Department was not available for more information Tuesday evening.