The 28-year-old Australian has not played since suffering a heart attack in the aftermath of Bradford's Magic Weekend defeat by Leeds at Manchester's Etihad Stadium on May 27. It happened two months after footballer Fabrice Muamba suffered a cardiac arrest during an FA Cup match between Bolton and Tottenham Hotspur.
"It was scary when they first told me - and I was there by myself," Purtell recalled. "At that point I didn't know anything about the situation and thought 'am I doing to die?'"
Purtell spent three days in hospital, where he underwent emergency surgery, and went through a series of MRI scans over the following months.
However, unlike Muamba, who was forced to retire, Purtell was given the all-clear in November to resume his career and has set his sights on returning to action before the end of next month.
In the meantime, he has pledged to help other heart attack victims and was unveiled as Yorkshire's first ambassador for Heart Research UK at a press conference at Odsal's Provident Stadium.
"This is a special one for me because I know at first hand what needs to be done in those scary situations," he said.
Purtell, who has made just eight Super League appearances, intends to see out the remaining two years of his contract with the Bulls and, after retaining the number four shirt, believes he is within six weeks of making his return. He resumed training three months ago but cannot do full contact work until he comes off his blood-thinning medication.
"I've got an appointment in London on the 13th of March and I'm hoping that maybe two weeks after that I should be back playing," Purtell said.
"I feel as good as I've ever felt, fitness and strength wise. Our conditioner has been pushing me really hard and I feel really good about where my body is."