EDMONTON — Asthmatics reached for inhalers, eyes burned, minor soccer was cancelled and fire alarms were triggered across the city as the campfire smell of B.C.'s burning forests descended Thursday on Edmonton.

When Jeff Ottewell heard about a provincewide air-quality warning, he went to the Kinsmen Sports Centre to check out the conditions for the five-kilometre running group he leads.

"I came to run the route to see what it's like for air quality. I don't know ..." said Ottewell, trailing off as he looked back at the route he just ran. Ottewell said he can usually run 10 or 15 kilometres with ease, but "after five, I was done."

While tackling hills, his breath was ragged. His time for five kilometres was about a minute and a half slower then usual.

"You'll know within the first five minutes whether you can do it or not," Ottewell said of those attempting to jog through the smoke.

Cindy Keith, the leader of Going the Distance Fitness Boot Camp, had 10 people show up to the Kinsmen Sports Centre for her Thursday evening workout session. Keith lowered the intensity level and left it up to her clients to decide whether or not they could exercise with the air quality warning.

"I'm not making the decision for you, unless you have asthma," said Keith, adding that she told those suffering from respiratory problems to take the night off. She also said she would usually bring her dogs along for the class, but left them at home on the advice of her veterinarian.

The barrage of smoke engulfing Edmonton originated hundreds of kilometres away from a series of wildfires raging across much of the British Columbia interior.

Smoke from those blazes was picked up by high winds Thursday and driven east into Alberta, prompting health offi cials to issue a provincewide air-quality warning that could last through the weekend.

"This is one of the more severe events we've had in quite some time," said Ogho Ikhalo, spokeswoman for Alberta Environment. "Talking with our ambient air specialists, they haven't seen anything like this since 2003, when there was the Kelowna wildfire."

The smoke was so bad that patients with respiratory conditions were told to stay indoors with the windows closed.

"It's potentially serious for some people if they are exposed," said Dr. Gerry Predy, senior medical officer of health for Alberta Health Services. "The levels of particulate matter are quite high in some areas."

Particulate matter can be absorbed into the lungs, where it can exacerbate existing health problems. People with asthma, bronchitis, emphysema, chronic obstructive pulmonary disease, or cardiovascular conditions, such as angina, and congestive heart failure may be most at risk, Alberta Health Services said.

The smoke led to a spike in emergency room visits at the University Hospital.

"They certainly have seen an increase in the numbers of asthmatics coming in because of the bad air quality," Alberta Health Services spokesman Kerry Williamson said. "That's both for adults and pediatric patients."

Even normally healthy people should limit strenuous activity outdoors until the smoke clears, Predy said. He said those who typically work outdoors, such as construction staff, may develop some throat irritation or a light cough, but should generally be OK within a day or two.