Fire officials are trying to figure out whether the heat led to the death of the 24-year-old firefighter.

Hamm died Thursday while fighting a fire near Mineral Wells, Texas, U.S. Bureau of Land Management officials said Friday morning.

Hamm was a member of the BLM’s Bonneville Interagency Hotshot crew, which is based in Salt Lake City, but he lived in the Boise area when he wasn’t working or going to the University of Idaho.

Hamm collapsed while working the 337 Fire and was being medically evacuated to a nearby hospital when he died. An autopsy will determine the exact cause of death, but the BLM said indications are the extreme heat was a primary factor.

Temperatures rose as high as 104 degrees in the area of the fire, officials said.

A team will begin investigating Saturday.

“Our entire organization deeply mourns the death of one of our own, Caleb Hamm,” said Robert V. Abbey, BLM’s national director. “His passing gives us pause to consider what truly matters in life. We extend our deepest sympathies and condolences to his family, friends and members of his crew.”

All crews on the 337 Fire were given a extra “safety stand-down” briefing Friday, said Paul Ries, a spokesman for the Texas Interagency Incident Management Team. Ries said the mood among firefighters Friday was somber.

“Everyone here is feeling the loss,” Ries said.

Between 200 and 300 firefighters and others attended a memorial service for Hamm Friday, the Fort Worth Star-Telegram reported.

Hamm was on a hotshot crew that was doing mop-up work and reinforcing fire lines on the 337 Fire, which was listed at 80 percent containment Friday. It was one of several fires in the state.

Hamm was a seasonal firefighter for six years. This was his first as a member of a hotshot crew, but it wasn’t a full-time job for Hamm at this point, fire officials said Friday.

Hamm was about ready to begin his senior year at the University of Idaho, BLM officials said.

Patrick Orr: 373-6619