The family likely died of hyperthermia and probable dehydration.

A family of hikers who mysteriously died two months ago along a hiking trail in California died from hyperthermia and probable dehydration, the Mariposa County Sheriff revealed during a press conference on Thursday (Oct. 21). The bodies of John Gerrish, Ellen Chung, their 1-year-old daughter Miju and their 8-year-old dog Oski were found on Aug. 17 along the Savage Lundy Trail near the Merced River in the Sierra National Forest, Live Science previously reported. There were no signs of trauma to their bodies, and investigators couldn’t immediately find a cause of death”Heat-related deaths are extremely difficult to investigate,” Mariposa County Sheriff Jeremy Briese said at the press conference. Since the bodies were found, the Mariposa County Sheriff’s department has worked with the FBI, toxicologists, and environmental and other experts to determine what caused the tragic deaths… More about this article in the link below…
https://www.livescience.com/california-family-found-dead-hiking-hyperthermia-dehydration