Health authorities have issued a high ozone warning as swathes of Australia enter day two of a severe heatwave.
Severe heatwave conditions have been forecast from the southern interior of Western Australia, most of South Australia to the east coast of New South Wales, Victoria and northeast Tasmania through to Thursday.
New South Wales Health said ozone levels were likely to rise this in western Sydney this afternoon due to a combination of heat and sunlight.
Ozone is created when nitrogen oxides from things like car exhausts and air conditioner fumes react with oxygen in the air on hot days.
It is colourless, but pungent, and can trigger a variety of health problems including chest pain, coughing and airway inflammation.
Director of Environmental Health Dr Richard Broome said the best way to avoid ozone was to limit time outdoors.
"Ozone levels are higher outdoors than indoors and generally highest in the afternoon and early evening," Dr Broome said.
"It's also important for people who have respiratory conditions to be extra cautious.
"If you have asthma make sure you're following your asthma action plan [and] you're carrying your reliever puffer on you.
"In case you do have an asthma attack and if your doctor has prescribed a preventer, make sure you're taking that as well."
Yesterday, Dr Broome also urged people to minimise physical activity this week and for relatives to keep a vigilant eye on vulnerable family members.
The mercury in Sydney's CBD is expected to hover around 31 degrees Celsius today, with humidity at 83 per cent.
But the city's western suburbs are expected to melt.
The Bureau of Meteorology (BOM) said temperatures were expected to climb to 40C in Richmond and 41C in Penrith.
Endeavour Energy said it had put off maintenance today at Glenbrook and Luddenham, with a spokesperson noting all work stops if the mercury hits 40C.
The worst of the heat will be felt inland, with the Riverina hamlet of Ivanhoe expected to reach a scorching 47C.
A hot air mass over the interior of #WA will migrate across to southeast #Australia over the coming days. Hot days and warm nights ahead for those areas. For latest forecast and warnings visit https://t.co/4W35o8i7wJ pic.twitter.com/LfwdbhnhBG— Bureau of Meteorology, Australia (@BOM_au) January 12, 2019
Elli Blandford from the BOM said the heatwave was due to a build-up of warm temperatures from inland Australia being dragged north over NSW and the ACT.
"Maximum temperatures are likely to be about 10 degrees above average for this time of year," she said.
On Monday, Adelaide reached 39C, while elsewhere in South Australia, Renmark hit 43C and Oodnadatta a scorching 47C. In Marla, police recorded a 46C on a patrol car thermometer.
The extreme heat has also been blamed for flying foxes and bats becoming ill and falling from trees and health officials in New South Wales have issued a bat attack alert for the Hunter region.
Officials say on average a person is bitten or scratched by bats every second day, which is unprecedented, with seven attacks in the last two weeks.
Most of those hurt were trying to help the bats.
Public Health Physician David Durrheim said two of the animals were infected with a virus similar to rabies.
"Two of the bats submitted for testing have actually had lyssavirus infection, so it is a real concern for us and for those people who have been exposed.
"They really are at risk of a potentially fatal infection," he said.
- ABC / RNZ