His sister, Rebecca Hertzberg-Pfaffinger, posted the news on Facebook this week, saying her brother was found dead in June in his car with his service dog, Hans.

The official cause of death is pending but his sister wrote she believes “he fell asleep and died from vehicular heatstroke.”

Much of the continental United States has experienced intense heat in recent weeks. The country’s west has been particularly hard hit, with record temperatures putting lives at risk.

Recurring heat waves are a marker of climate change caused by humanity’s use of fossil fuels, according to scientists.

Gregory was found dead in a suburb of Phoenix, Arizona in the southwest US.

“Alf” ran from 1985 to 1990, with Gregory playing a child who became best friends with the titular Alien Life Form.

The actor was born May 26, 1978, in Encino, California.

His star turn as a child also earned him a number of roles in commercials as well as appearances on shows including “The Twilight Zone.”

He left the entertainment industry in the early 2000s, joining the United States Navy.