A 65-year-old San Diego man was found dead apparently from extreme heat at Death Valley National Park in California, where his car had two flat tires and a non-functioning air conditioning system as temperatures soared into the triple digits, park officials said Wednesday.

A maintenance worker for the National Park Service found the man's body on July 3 around 10 a.m. local time in a sedan, the park said in a news release. The car's tracks had run along a road's shoulder and rocky berm before veering farther away from the paved road.

"The vehicle did not crash but had two flat tires when stopped. The initial investigation suggests that heat-related illness may have caused the driver to run off road," the park said in the news release.

The day before the man was found, the high temperature was 126 degrees Fahrenheit while the overnight low temperature was 98 degrees, park officials noted.

"The vehicle was found to be operational and was not stuck, however the air-conditioning in the vehicle was not operational. The driver's window was found down, further indication that the air conditioning was not functioning when the man was driving."

Park rangers, the Inyo County Sheriff's Office and Inyo County Coroner's Office responded after the man was found unresponsive 30 yards off North Highway. The man was declared dead on the scene, according to the release.

Extreme heat deaths are the leading cause of weather-related deaths in the US. An average of 702 heat-related deaths occur every year, according to the US Centers for Disease Control and Prevention. Deaths can result from heat stroke and related conditions as well as cardiovascular, respiratory and cerebrovascular diseases, the CDC notes.