Australia’s southern states are scorching in extreme heat that could break temperature records in Victoria and South Australia on Tuesday.
At Ouyen and Mildura in north-west Victoria, temperatures of 49C were forecast for Tuesday afternoon. If reached, they would break the state’s all-time temperature record of 48.8C, set in Hopetoun on Black Saturday in 2009. By 1pm, temperatures of 46.2C in Ouyen and 44.8C in Mildura had been recorded.
At Ouyen and Mildura in north-west Victoria, temperatures of 49C were forecast for Tuesday afternoon. If reached, they would break the state’s all-time temperature record of 48.8C, set in Hopetoun on Black Saturday in 2009. By 1pm, temperatures of 46.2C in Ouyen and 44.8C in Mildura had been recorded.
In Adelaide, the mercury hit 40C before 9.30am on Tuesday, after overnight lows of 35C, BoM observations showed.
Extreme heat is the most common cause of weather-related hospitalisations in Australia, and kills more people than all other natural hazards combined. What does exposure to extreme heat – such as a temperature of 49C – do to the body?
Once temps hit more than 37C and 100% humidity, the human body loses the ability to regulate it’s temperature through sweating.
It’s dry as a bone here right now. (That’s good)
Also means it’s all a big tinderbox. (That’s bad)
It makes evaporative air conditioners work better (That’s good)
Isn’t this called wet bulb or something and lethal?
That was it, yes!
Actually at 100% humidity the highest survivable temperature for a human is 35 C° wet bulb temperature.
But that is with everything else being perfect, being healthy, in the shade, and perfectly hydrated, and zero physical activity.
A more realistic maximum survivable wet bulb temperature is closer to 30 C°. But 35 C° is the absolute maximum, where above that everybody dies.
Sorry, but that’s wrong. WBGT takes radiative heat into effect when it’s calculated. The sun and shade effectively have two different WBGT readings. That’s why its measured with a black globe. Protocol is to measure ~2 meters heigh in direct sunlight away from structures that block wind so you get the worse case scenario. Like any whether reading, its localized.
I’ve worked in mines in the desert in South Australia where temps semi regularly hit 46-47 degrees.
It’s OK (ish) because the humidity is low. But you can drink a litre an hour all day (11+ hours) and not need to pee. All that water goes somewhere.
The underground workings are often more dangerous, with lower temperatures but higher humidity. Once wet bulb temps get above 34 degrees underground personnel need to retreat from the area and the only work that can be done there then is work to fix the ventilation.
There’s heat stress meters that measure wet and dry bulb temperatures and airflow, and can basically compute cooling power in watts. Not enough cooling power -> everyone out.
Yeah, in those conditions, you live and die by wet bulb temperatures.
I can only imagine, as I sit on the Stockholm metro with cold and damp feet after walking through snow and some slush to get to the bus earlier.
I am happy to hear that you have rules and regulations for these eventualities.