Cold Weather 'May Be a Contributing Factor' in Kristin Cavallari's Brother's Death, Sheriff Says

Michael Cavallari went missing the day after Thanksgiving

Photo: Courtesy Grand County, Utah, Sheriff's Office

Police believe Kristin Cavallari‘s brother Michael may have died from exposure to cold weather after crashing his car off a Utah highway.

“We think it may be a contributing factor, but we won’t know for sure until we get the autopsy results back,” Sheriff Steven White of Grand County, Utah, tells PEOPLE.

Autopsy results will be available in six to eight weeks depending on when the toxicology report comes out, White says. There is no indication of suicide or foul play at this point, and White says search patterns indicate Michael, 30, was “disoriented” before his death.

On Thursday, investigators found Michael’s body three miles from where they discovered his abandoned car earlier this week.

“We want to thank everyone for their love, support and prayers during this very difficult time. We have just been informed by the authorities my brother’s body has been found,” Kristin, 28, told PEOPLE in a statement Thursday. “This is a very painful time and we are still processing it all. We kindly ask everyone please respect our privacy during our time of grieving.”

Later, she paid tribute to him with an Instagram of the siblings as toddlers.

“My heart is in a million pieces,” she wrote. “Mikey, I could always count on you to make me laugh. You had such a good heart and will be forever missed. I’m at a loss for words but I know u are in a better place and finally at peace. I love u so much RIP.”

The tragedy comes just weeks after she welcomed her third child, daughter Saylor James, with her husband, Chicago Bears player Jay Cutler.