The fire, reported 11:07 a.m., heavily damaged a house in the 1300 block of Farringdon Drive, fire Capt. Mary Gutierrez said.
Robert Sotelo, who lives about two blocks away, said he was walking through the neighborhood with his girlfriend and 18-month-old daughter when he saw smoke, realized the home was burning and called 911.
The front door was open and he saw a woman standing inside, surrounded by smoke, Sotelo said. The woman had no shirt on, and would not come out.
Gutierrez said the 85-year-old woman, who did not appear to speak English, had been in the shower when the fire started and was alerted to the blaze by a smoke detector.
As Sotelo tried to get the woman to come out, she instead turned and went farther into the home, he said.
He went in after her, ducking under the smoke, but she still refused to exit, so he ran back outside and took a deep breath.
Sotelo then re-entered the home and found the woman in a bedroom. By then, the fire had intensified and it was too smoky to go back out the front door, he said.
The woman was trying to pull some clothes on, he said. Knowing he didn't have much time, he acted.
"I just took my shirt off and threw it on her, and we went out the window," he said.
As he lifted the woman through the window, another man ran up and helped them exit.
The woman was not injured, and neither was Sotelo.
"I was holding my breath the whole time and staying under the smoke," he said.
The one-alarm fire caused extensive damage to the kitchen, and there was smoke damage to the entire house, with some charring in the attic, Gutierrez said. The cause has not yet been determined.
Five adults and three children were displaced, she said. The American Red Cross has been called to assist the residents.
Gutierrez said firefighters arrived in about five minutes, but that Sotelo had already gotten the woman out by then.
"The fact that she had a working smoke detector was probably one of two things that saved her life" -- the other being Sotelo, Gutierrez said.
Since Sotelo had "very gallantly" given the woman the shirt off his back, he was shirtless when firefighters arrived, so one firefighter gave him a San Jose Fire Department shirt, Gutierrez said.
Sotelo stayed around for a while talking with firefighters, then said a casual goodbye to the woman he saved and headed back home.
"I shook her hand and just told her to take care," he said.
Sotelo, who works at OnTrac Shipping, said he doesn't have any plans for the day other than heading to work later. He said he doesn't feel like a hero.
"No, I feel pretty normal," he said.