A U.S. hiker vividly recalls the night one of his fellow campers was pulled from his tent and attacked by a polar bear in Torngat Mountains National Park in northern Labrador.

Matt Dyer, a lawyer from Maine, was badly injured during the attack at around 1:30 a.m. AT on July 24.

Richard Isenberg was with Dyer and six other hikers as part of a Sierra Club hiking trip to the remote park.

He said the group woke up to the sounds of Dyer screaming as he was dragged from his tent.

"He only screamed twice, and I saw the bear dragging the tent and then pulling Matt out of the tent and carrying him off," Isenberg told CBS News.

A helicopter arrived to take Matt Dyer to hospital six hours after the group of hikers called for help. (Photo courtesy Kicab Castaneda-Mendez)

The bear ripped through the electric fence the group had set up around their campsite that night.

When the campers realized what was happening, they acted quickly and fired flares to try to scare the bear away.

Isenberg , who is a doctor, ran toward Dyer once the bear was out of sight, but said he didn't know what to expect when he got there.

"It was clear to me that the bear had him by the face because he had numerous puncture wounds all around and by the neck," he told CBS News.

Isenberg has not been a practising physician for 14 years, but said he sprang into action without any hesitation.

"As soon as it happened, I was on. I was on duty, I was on, so, get me this, do this, I need that, get me some more towels," Isenberg told CBS News.

He said the only equipment he had to work with was a small first-aid kit. The group called for help, but a helicopter took six hours to arrive at the site.

Dyer was loaded into the helicopter and, along with Isenberg, was flown to a hospital in Quebec and later transferred to the intensive care unit at Montreal General Hospital.

"There is no sound more welcome than that chopper coming over the hill after all those hours of feeling both afraid that the bear was going to come back or bring his friends, God forbid," said Isenberg.

Dyer is still recovering in Montreal.

Calling for policy change

Another hiker, Kicab Castaneda-Mendez from North Carolina, who was on the trip with Dyer and Isenberg , said he thinks Parks Canada should strongly consider changing its policy for those visiting the Torngat Mountains.

Parks Canada strongly advises visitors to hire an armed bear guard during their stay, but it is not mandatory.

The Inuit bear guards are hired through the Nunatsiavut base camp set up within the park.

However, Castaneda-Mendez said his group was never offered the armed bear guard, and said that the outfitter they hired insisted it was not necessary. He said his group was under the impression the portable electric fence was an adequate deterrent.

"The bear fence advertisement said that it works as a deterrent," he said. "There was no reason to believe that that wasn't adequate." He added that Parks Canada accepted the group's bear deterrents as adequate.

The group entered the park through northern Quebec, and was supplied by a private outfitter in that area.

Castaneda-Mendez said he works as a process improvement consultant in the U.S. and has offered his service free of charge to Parks Canada and the outfitter that his group used to help make changes to ensure appropriate safety policies are being executed.

The group of hikers spotted a mother polar bear and her cub on their first morning in Torngat Mountains National Park. (Photo courtesy Kicab Castaneda-Mendez)

According to the Parks Canada policy, there is not only supposed to be a briefing for all travellers before they enter the park, but also a video about bear safety that they are supposed to watch.

Castaneda-Mendez said the outfitter they used didn't have the video to show them, so they entered the park without viewing it.

Peter Deering, who is with Parks Canada, said this incident has prompted the agency to undergo a review of its policy about preparing travellers before entering the park.

"What we will want to do in the future is to tighten up, to a degree, the registration process in terms of making sure that not only do the trip providers understand some of the hazards that are inherent in the national park, but that every individual travelling with a group understands that there is some risk here beyond those risks that are already clearly defined on the website," Deering said.

He also said they would be following up with outfitters to make sure everyone is on the same page in terms of safety precautions.

"Enforcing, making sure that an individual outfitter reinforces those messages to his clients, or her clients, it's a huge challenge for sure," Deering said.

"And in our communication with outfitters we want to make sure that they understand what our safety procedures are, what we recommend in terms of safety."

Torngat Mountains National Park was founded in 2005 and covers much of the northern tip of Labrador.