'True heroes': Aussie's brilliant response to SCG smoke threat

Day two of the Sydney Test shapes as the biggest smoke challenge for cricket officials with temperatures expected to soar and hazy conditions forecast.

Fresh from the Aussies’ big win over the Kiwis at the MCG, more attention is likely to be on the air than the ground for the third match against New Zealand as the bushfire crisis rolls on.

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A Big Bash match was abandoned in Canberra this month and authorities will treat smoke like rain at the SCG by calling players from the field if conditions become unsafe or visibility is poor.

Aussie players this week have been at lengths to insist cricket was far from the most important issue in the fire dramas, with Nathan Lyon paying tribute to those devastated by the fires.

"Let's put this in perspective, we play cricket and there are people out there losing their lives and livelihoods," Australian spinner Nathan Lyon said.

"A bit of smoke doesn't worry us. We play a game. The true heroes of this world are the firefighters fighting fires."

Smoky conditions are set to wreak havoc during the third Test at the SCG. Pic: AAP

Nevertheless, temperatures are expected to hit 45 degrees in Sydney's west by day two on Saturday, with the city forecast to be slightly cooler closer to Moore Park.

The Bureau of Meteorology is concerned the city's air quality will again become poor into Sunday, with winds also expected from the north.

Smoke issue tough for cricket officials

"With that second very hot spell, we would expect to see a continuation of smoke haze and poor air quality into the weekend, if not further (deterioration)," a BoM spokesman said.

More than 3 million hectares of land has been burnt in NSW's fires this summer.

The issue of smoke is a difficult one for cricket officials.

The Australian Institute of Sport lists an air quality index (AQI) rating of 150 as hazardous for intense exercise while the NSW governments has 200 regardless of activity.

However the ICC's guidelines only state that it is not hazardous until an AQI of 300 is reached.

Cricket Australia consider all guidelines when considering if venues are safe for play, while the Test will be in the hands of ICC umpires.

Meanwhile there are also questions over how the index is measured.

It is judged on a rolling 24-hour measurement, meaning it takes a longer for the AQI to rise even when smoke blows in.

CA and the players' association are in the midst of developing a proper framework for dealing with smoke, with Dr John Orchard involved.

Cricket has already been affected in Sydney in the past month, with some men's and women's grade matches called off.

Paramedics were called at least twice to one game as two non-asthmatic players experienced breathing difficulties.

NSW spinner Stephen O'Keefe also labelled conditions "shocking" and "toxic" in a Sheffield Shield game which continued at the SCG while it was smothered by smoke.