A Calgary teacher is being credited with saving a student’s life after she started to choke on a sandwich during class.

Gerry Doak, a Grade 10 science teacher at William Aberhart High School, is crediting some lifesaving training for how the situation played out.

Two weeks ago, a student started choking during Doak’s morning class.

"It's sort of like sort of hollow gulp and you're aware that there's no breath getting through," said Doak.

"That scared me. Put the fear of God into me, frankly."

Doak had taken first aid and CPR training. He jumped in and performed an abdominal-thrust  that has saved the lives of thousands of choking people.

Calgary Board of Education offers first aid training in accordance with provincial guidelines.

Training isn't mandatory, but a certain number of staff at each school must have completed it.

But on the advice of William Aberhart's principal, Doak and more than 60 other staff and teachers voluntarily signed up.

"I've always been sort of resentful — don't tell my boss — that I have to take this first aid training. But thank God. If I didn’t take this training, I would have had no idea what to do under the circumstances."