After being trapped for 12 hours, it took Jonathan Metz, a Connecticut man whose arm became stuck inside the furnace he was repairing, an additional six hours to "psych" himself up enough to amputate his own arm using a the blade of a power saw.
Describing his ordeal publicly for the first time since paramedics found him in the basement of his suburban Connecticut home on June 10, Metz called the experience "surreal."
Speaking to reporters at St. Francis Hospital, where he underwent surgery Friday to receive a muscle graft on his left shoulder to be fitted for a prosthesis, Metz said he felt "blessed and more than fortunate to be here today."
Metz's arm had become caught between heating cores inside the boiler on Monday. Within hours, Metz, 31, could smell the flesh of his crushed arm beginning to rot, the telltale sign of life-threatening infection.
"Very quickly it became apparent to me I had a major problem," he said.
Eighteen hours into the ordeal, he fashioned a makeshift tourniquet and, using the blade from a power saw, began by hand to sever his left arm.
"As luck would have it I had the blades I would use with some of my power tools," he said.
He floated in and out consciousness, drinking water leaked from the furnace. He said he used a bloody flip-flop to scoop up the water.
Doctors said the decision he made saved his life.
Metz began cutting into his bicep, about halfway between his elbow and shoulder.
"The cut was going well about halfway through," but then an alarming amount of blood started gushing, the tourniquet became ineffective and he had to stop cutting.
When paramedics found him, they pried the furnace open, using a spreader typically used to remove injured people from car wrecks, and completed the amputation.
"People wonder how someone could go to that extent and remove his own extremity. But he saved his life by removing the non-viable part of the extremity. The wound released toxins that were circulating through the body. Cutting away that dead tissue saved his life," said Dr. Scott Ellner, the surgeon who operated on him Friday.
Metz, who said he is engaged and has a wedding date set, said thinking about his fiancee and family helped get him through the ordeal.
"What got me through this whole thing was thinking about family, friends my dog. I had a lot of living to do," he said.
Metz, who lived alone, was rescued Wednesday after a friend, Luca DiGregorio, grew worried when he did not show up for work and missed a Tuesday night softball game.
Metz did not answer the doorbell when DiGregorio stopped at his home Wednesday, but he said he saw Metz's beagle "yipping at the back door." DiGregorio called police, who found Metz in the basement.
"I was a little worried, especially when the first cop showed up," DiGregorio told reporters. "Then more showed up, and then the ambulance showed up, so it got a little nerve-racking."
Paramedics had to cut open the furnace and fully sever Metz's arm to free him from the furnace.
"We used the spreader normally used to tear a car apart. It was a pretty old boiler and this particular unit was very strong. We had to cut a support rod inside the boiler and spread apart the two halves, breaking the cast iron in order to extricate the arm from the unit," said Battalion Chief Matthew Stuart of the West Hartford Fire Department.
Doctors said Metz was recovering well.
For anyone wishing to help Jonathan pay for a prosthetic arm and therapy, his family and friends have established an email and bank account to accept donations.
ABC News affiliate WTNH contributed to this report.