When German forces began their occupation of Hungary in 1944, Thomas Gerendas was living in Budapest and nearing his bar mitzvah, the traditional coming-of-age service held when a Jewish boy turns 13. His life was saved by a stroke of luck, when two local women — sisters who were Catholic — hid him in their water closet.
Judaism was an important part of his life as a young boy. His parents weren’t highly observant, but even as a child Mr. Gerendas was fascinated by religion. He often led prayers and holiday celebrations for his family, said Esther Briggs of Bloomington, Ind., his oldest daughter.
As Mr. Gerendas learned more about the Christianity from those he lived with during the war, he began following Christian traditions. Through his life, he continued observing religious practices from Judaism and Christianity, passing on his spiritual beliefs to friends, family, and colleagues.
“His love for God infused all that he did with a depth of conviction and strength,” said Barbara Pless, who is compiling a collection of stories that Mr. Gerendas and his wife, Jutta, liked to share. “He held himself to the highest standards in all of his conversation and activities, and although there was much humor, there was never anything false or of questionable taste.”
Mr. Gerendas, a Holocaust survivor who founded Temptronic Corp., which pioneered new methods for controlled temperature testing, died in his home Dec. 20 from complications of an injury related to his Parkinson’s disease. He was 84 and had lived in Wayland for more than 40 years.
Throughout the decade since his Parkinson’s diagnosis, Mr. Gerendas went on daily walks around his neighborhood. As the illness progressed, the walks became shorter, but he remained persistent. Neighbors grew to expect to see him and went outside to walk along with him or bring him food.
“He was like the mayor. I’d be on walks with him and there would be three cars, four cars, lined up to talk to Tom on his Parkinson’s walk,” Briggs said. “I met so many cool people just by going on walks with my 84-year-old father.”
Most neighbors, like Teresa Amabile, didn’t know Mr. Gerendas had Parkinson’s until years after his diagnosis. Upbeat and spirited, he never talked about the illness.
“You could hear the smile in his voice . . . you could see the effort,” said Amabile, who met Mr. Gerendas when she and her husband moved onto the same Wayland street almost 40 years ago. “He got out there every day unless the weather was really bad. Until he got really quite impaired, he would even go out there in the dark.”
An only child who was born in Budapest, Thomas Gabriel Gerendas was a young adult when he took the last name of an uncle.
He graduated from the Berzsenyi Daniel school in 1950 and went to the Budapest University of Technology and Economics, where he studied mechanical engineering.
In 1956, he left his home country after the Hungarian Revolution and moved to Montreal, where he met Jutta K.O. Merkel.
Because of their backgrounds, they were an unlikely couple.
Mr. Gerendas was a Holocaust survivor from a Jewish family. She was from a German family. Her father was an officer in the German Army under Hitler, and her uncles were SS officers.
“She laughed and said, ‘Well, this must be God’s sense of humor,’ ” Briggs said of her mother, “but I don’t think either of them could have married some Canadian or American person who hadn’t gone through that.”
They married in 1963 and moved to Arlington about four years later. In 1973, they moved to Wayland, where they raised their three children.
After moving to Massachusetts, Mr. Gerendas founded Temptronic Corp., using technology he created to revolutionize the way equipment is tested in extreme temperatures.
For his accomplishments, he received a John Fluke Sr. Memorial Award, which honors executives who lead their companies with innovative engineering or business management.
“He was a very ingenious, creative person,” said Fumio Taku, who worked with Mr. Gerendas at Temptronic for about five years.
“He was an entrepreneurial person, but also a . . . people person, and that’s hard to come by.”
Taku said Mr. Gerendas was an unusual leader who often walked around the production floor to talk with employees, whom he urged to spend evenings and weekends away from work.
“We were frugal enough to enable us to stay independent and to allow us to survive without sacrificing our private lives and ethical principles, while generating sufficient cash for growth,” Mr. Gerendas wrote in a memoir. “If this sounds idealistic, it seemed to pay off handsomely through the stability of the families in the company.”
Mr. Gerendas had friends around the world from his lifelong membership in a Jewish Boy Scout troop, his daughter said.
The troop formed after non-Jewish troops rejected the boys, and its members are still in contact with one another.
“I don’t feel like you can replace childhood friends who have known each other for seven decades and have lived through that kind of trauma,” Briggs said.
Mr. Gerendas was diagnosed with Parkinson’s in 2006, his daughter said, but even as his physical strength waned, his faith never wavered.
“He never complained about it once,” she said. “I have said, ‘Dad, I would be wailing against God or this disease,’ and he would just look around at me from his walker or his little walk to his bedside and say, ‘Who am I to question God?’ ”
A service has been held for Mr. Gerendas, who in addition to his wife and daughter leaves two other daughters, Maria O’Laughlin of Hingham and Rebecca Hansen of Beverly; and four grandchildren.
Many who knew Mr. Gerendas will miss the optimistic faith he brought to their lives, either through prayer or spontaneous words of wisdom. When Mr. Gerendas saw Amabile and her husband on their street, he often would offer a prayer.
Placing his hands on their shoulders, he would close his eyes, bow his head, and pray.
“He did those walks for himself, certainly for his own health, but he was doing something for us,” Amabile said.
“He was doing something for all of us on this road. He was inspiring us, and he was showing us that he cared by everything he said.”