Brian Stroschein had been treated at the University of Utah Burn Center in Salt Lake City since he was brought there in critical condition Dec. 20.
"With a saddened heart, I need to let you know that my precious husband Brian passed away peacefully this morning," Kathy Stroschein wrote in a post on a special Facebook page set up by family and friends. "He was surrounded by his family. His spirit was willing but his body couldn't fight any longer. I want to again say thank you for all of your prayers, love and support you have shown us. We love you all."
Stroschein suffered burns on more than 75 percent of his body and had third-degree burns on his hands and face.
He died at 4:43 a.m. Thursday, a hospital spokesman said.
Stroschein, who worked as an engineer at Hewlett-Packard's Boise operation, had gone hunting near Grangeville when a propane tank in his utility trailer exploded.
A vigil is planned for March 7, with a funeral the following day. Additional details will be released later.