Doctors warn there are biological limits to temperatures we can survive, and exposure to extreme heat can provoke a heart attack

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?

  • chonglibloodsport@lemmy.worldEnglish
    1·
    17 hours ago

    At 230C without a sealed pressure vessel there’s no way the temperature probe is still functioning as a wet bulb thermometer. That temperature in your oven is going to be dry bulb.

    A wet bulb thermometer measures the temperature with the probe completely immersed in liquid water. At 230C there won’t be any liquid water at anywhere near atmospheric pressure. 230C corresponds to a saturated steam pressure of 27 bar or 2.7MPa (391 PSI). That’s nearly 10 times the pressure in a pressure cooker at max temperature.

      • chonglibloodsport@lemmy.worldEnglish
        2·
        13 hours ago

        Just for further reference, 27 bar of pressure is equivalent to 268 meters depth under the ocean. There’s no way a home oven can be built to contain that amount of pressure.

        You may set your oven to 230C and put a dish of water in there, but if you placed a wireless temperature probe in the water the temperature would be at or below 100C until the water boiled away and the probe was exposed directly to air and steam. No matter how hard you tried you could not get a reading much above 100C with the probe immersed in liquid water.

        • vane@lemmy.worldEnglish
          1·
          12 hours ago

          Looks like those ovens have steam pump and drain pump. Interesting, how big would be device that would sustain 27 bar pressure ?

          • chonglibloodsport@lemmy.worldEnglish
            0·
            11 hours ago

            Depends on the capacity, but in general it would have really heavy reinforced walls, like a really high pressure boiler.

            I have an instant pot and an espresso machine. The instant pot can manage maybe 2 bar, the espresso machine up to 4 (in its boiler). Both are pretty heavy construction.

            • vane@lemmy.worldEnglish
              1·
              11 hours ago

              I figured out so far that Locomotive engine have 200-250 psi that is 13-17 bar. Maximum implemented boiler pressure so far is around 300 psi 20 bar. So it probably would be a world record machine. :)