The new year brought thick smoke haze to Canberra with the city experiencing among the worst air quality conditions to ever hit the nation's capital.
By midday on Wednesday, the air quality in Canberra's south reached a level more than 20 times above hazardous and the recorded index rating was higher than the world's most polluted cities.
The dense smoke haze engulfed Canberra on Tuesday night from fires burning at the South Coast.
Acting chief health officer Dr Paul Dugdale said on New Year's Day the capital experienced the worst air quality conditions since ratings began to be measured 15 years ago.
Dr Dugdale said there were a dozen presentations to Canberra Hospital in the 24 hours to noon on Wednesday for smoke-related conditions.
"It's a particularly difficult time for people with heart and lung conditions who are sensitive to smoke, our message to them is to follow your doctor's advice, take your medications and if you have got an asthma action plan, put that into effect," he said.
All Canberrans were advised to avoid physical activity during the heavy periods of smoke.
Emergency services fielded more than 150 calls to triple zero about the smoke and it set off more than 250 automatic smoke alarms across Canberra.
ACT fire and rescue chief officer Mark Brown said crews responded to alarms at a range of premises including government buildings and hospitals.
"Fire and rescue had to respond methodically to those buildings and investigate and reset all those alarms," he said.
"It took a lot of resources and we actually didn't even finish the task until early this morning."
As of 6pm on Wednesday, the most recent update, the Monash air quality station had an index rating of 4998. Anything above 200 is considered hazardous.
In the north, the Florey air quality station had a rating of 3845 and the Civic air quality station was at 3769.
The visitor centres at Tidbinbilla Nature Reserve and Namadgi National Park were closed due to the poor air quality.
ACT Rural Fire Service chief officer Joe Murphy said watch towers in Canberra only had 500 metres visibility and this hampered situational awareness on the very high fire danger day.
The same poor visibility affected Canberra Airport on Wednesday, causing the cancellation of an international flight from Doha.
According to the Bureau of Meteorology, visibility on a clear day is 10 kilometres.
A Qantas spokeswoman said low visibility from the bushfire smoke haze had caused minor delays. Virgin said there had been no delays.
Little reprieve is forecast for the coming days. On Wednesday night winds were forecast to push more smoke into Canberra.
ACT Health said anyone with concerns about their health should seek medical advice from their doctor. And anyone experiencing wheezing, chest tightness of difficultly breathing should seek urgent medical attention and in the event of a medical emergency call triple zero.
People who are sensitive to smoke and air pollution includes:
Common symptoms people may experience with heavy smoke include:
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