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.
This temperature happens a lot in Taiwan and is also 100% humidity. It’s not comfortable.
South Australia doesn’t have humidity.
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.
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.
Yeah, in those conditions, you live and die by wet bulb temperatures.
Now, please correct me if I am wrong, but would drinking cold stuff balance out the temperature difference? Like say it’s 40c wet bulb, but you have access to cold water to drink, would that work?
You couldn’t physically drink enough water. Math is not my strong suit but this seems pretty straightforward.
It takes one calorie to raise the temperature of 1 gram of water by 1 degree Celsius, by definition. Plugging in some numbers (a liter of water starting at a very frosty 1 C) takes almost 40 kilocalories or about 160 kiloJoules of energy. That’s like half of your “simply existing” calories per hour, so you’d need to consume 2 liters of ice-cold water every hour (and excrete every gram of it to 40, which you aren’t doing with your living body) just to break even.
It gets more complicated when you factor in evaporative cooling and I already said I’m not a math-man but the environmental factor is simply too strong for biology.
Fair, I was uncertain if the cold water would be sufficient. Thanks for your reply!
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)
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.
Yup. Wet-bulb conditions are no joke and can kill, making functioning A/C a life-saving technology if not an outright requirement for survival.
Isn’t this called wet bulb or something and lethal?
That was it, yes!
1-100 Celsius is about water freezing —> boiling and I’ve always been confused about why it’s so eminently logical to understand the weather by that scale.
1-100 Fahrenheit, meanwhile, is a really reasonable approximation of the habitable range of temperatures.
And you just showed this by having to establish for everyone that the upper bound of habitability is 37C. A completely random number anyone would forget.
No one “forgets” temperatures dude, 17°C might be meaningless to you but to me it’s just shirt and light jacket weather. Nobody forgets what the body temperature in Celsius is. It’s two digits, your brain can do it.
Fahrenheit simply puts the human at the center where physical phenomena like water freezing and boiling happen at “random” points on its scale, while Celsius takes two simple, constant (as long as you’re not on a mountain), verifiable points based on physics, where the temperature of a human body falls on a “random” place on it.
The point is very simple: if you have an unlabeled thermometer and need to calibrate it, you stick it in freezing water, mark 0, stick it in boiling water, mark 100, divide into equal segments, and it will be exactly right. If you want to do the same for Fahrenheit, you need another reference thermometer. (Unless you happen to have the same unspecified mixture of water, ice, and ammonium chloride that Fahrenheit supposedly originally used to mark the 0 point)
I appreciate the elegance of your field calibration, but it will not be “exactly right.” The boiling point of water is readable repeatable but sensitive to altitude and the contents of the water. Freezing is also sensitive to salt and mineral content, but even more basically: where’s this “freezing water” you can stick your thermometer into, that’s reliably == 0 degrees? Ice keeps getting colder, and melted water can be any temperature above 0.
Good in theory, but even if field calibration were a real need, it’s not very exact. And anyway, if you can work all that out, you can do it for F or C. Since no one will every forget 212 and 32, as you point out.
A substance undergoing phase change will hold its temperature until the change is complete. That means that once water starts freezing, it will be 0°C until it is all ice. Same goes for ice thawing. Yes only pure H2O will freeze at exactly 0°, but unless you deliberately put some shit in it it will be very, very, very close. Boiling is a bit more sensitive, but still a lot less than the natural variance between body temperatures in normal conditions.
You’re taking the procedure literally, but it was just to get a point across. Also, using the freezing and water boiling points of water was used to define Fahrenheit too for most of the 20th century.
Well, that last point suggests that you don’t need the Celsius scale to use water’s phase changes as a reference / definition. Which undermines your entire case for Celsius being superior because it’s based on that.
All I’m saying is that F has some human usability merit in that the scale just happens to corresponds nicely to a human quality. Since any scale can use physical qualities as a definition, why shouldn’t we use one that’s more human-centric.
From my side, it doesn’t because what the fuck is 40 f? I have no clue. The human merit you’re referring to is all due to what you have been taught
I am sorry, but you are wrong, however you are not wrong at what you might expect me to call you out on.
There is nothing inherently superior with F for “habitable” temps, both C and F works fine for that, for me who is used to C, talking about body temps of 37 makes sense to me, for me 98.6 seems completely wrong.
It all boils down to what we are used to.
It’s funny how it’s supposed to be great to measure “human temperatures”, yet 98.6 is normal and 100 is a fever.
It’s even sillier than that.
https://en.wikipedia.org/wiki/Fahrenheit#History
https://med.stanford.edu/news/all-news/2020/01/human-body-temperature-has-decreased-in-united-states.html
I agree that celcius is better, but this is a terrible point. This would be a biological reaction. Different topic.
Terrible point? The body temperature is literally the upper defining point of the scale. Except that Fahrenheit chose that point to be 96, and he was still wrong.
Yes, it uses the the human body in a healthy state to determine a range of habitable temperatures. There is no math involved that is even remotely concerned with temperatures in a sick person. Not my opinion. Fahrenheit factors in general habitability, it doesn’t take into consideration something like a specific group of elderly people who’s temperature runs low due to low blood pressure.
Whoa that’s a lot of being butthurt about nothing.
I’m just saying, if you’re going to make a scale that is defined by body temperature, why tf would you make that point 98.6 or 96 instead of 100? The “you need to remember 37” argument doesn’t make much sense if you need to remember 98.6 does it?
You are not reading me. I am 100% agreeing with you that the scale is fucking stupid and illogical. I’m trying to point out that it does not, no matter how much you say, consider someone with a virus or illness.
I’m saying to make the point we both agree on, it’s valuable to understand this.
You may be shocked to discover that we can also measure the temperature of water in F.
Your talking right and wrong is beside the point. No one scale is superior for any use, strictly speaking. The point is that 1-100 in F relates in an intuitive way to the range of human habitation. That’s a more intuitive thing to base a scale on in my opinion. Now tell me my opinion is wrong, I dare ya!
Do you respond to everything everyone tells you with a complaint that they haven’t already told you it before? This is a discussion. I’m not defending a written doctorate thesis.
C is highly intuitive if you are a water molecule. Absolutely brilliant for those chaps. Wait… I have assumed this whole time you are human. Are you a water molecule?? You never mentioned that before!!
You brought it up in a completely irrelevant post, do you always bring uo irrelevant point in a discussion and get annoyed when people discuss your irreleveant tooic?
It is in fact getting to be a bit of a hobby to mention Fahrenheit’s good points, just to see people wet themselves and complain when their worldview shatters.
My worldview isn’t shattered.
I’d much rather know if I should expect ice or wet pavement outside than whatever 1 degree F is. What’s the difference to me, functionally, between 0 and 1 degrees F?
And 100 degrees F could be a nice day or an absolute hell depending on humidity. So it’s still not useful.
You just think it makes more sense because it’s what you are used to.
I explained it in objective terms. Human habitability range. We’re in a thread about weather exceeding what humans can withstand. That point is pretty easy to remember in F, as if the scale were determined by the extremes we can withstand, a fairly relevant range, regardless of what anyone is “used to.”
Fahrenheit wanted repeatable, laboratory-friendly reference points, not abstract physics.
These were the anchor points:
They could have chosen 100 °F for the human body, but then the math works out oddly for other common calculations (e.g., the freezing point of water is ~33.33). They went with 96 because it’s easily divisible by 2, 3, and 4 (perfect for halving, quartering, and thirding with 18th-century tools). This placed the freezing point of water at exactly 1/3 the way up to the top anchor of 96.
It’s a system designed for convenience with ancient tools and ways-of-life. The boiling point of water wasn’t used because it was too difficult to reliably reproduce at the time.
What stands out here is that this does not necessarily model after some kind of “habitability zone.” Such a zone is only prescribed post-hoc, with the conventional understanding of Fahrenheit -> comfortability conveniently engrained in your intuitive reflex already.
The truth is, habitability changes based on factors like humidity too. I’ve experienced 120F that wasn’t so bad, dare I say it was a “nice toasty summer.” In contrast, I’ve experienced 75F with very high humidity and I wanted to die.
I agree that Celsius’ definability and reference points are more sensible.
All I ever say on this is that F has its appeal in everyday usability terms, because of how nicely 0-100 encapsulates our comfort zone. Not that it’s designed that way, it just happens to work nicely.
And whenever I say this much, people (not you) begin screaming at me about how I need to live my life by water’s phases changes :/
Yeah. I see your point that it’s a good rule of thumb, given it should as the human body temperature sits so close to 100F and that’s upper bound used. I see your point.
Boiling water hard to reliably reproduce? What?
I like the idea that it’s hard to boil water, but easy to find a person whose body temperature is exactly the same as the reference point.
As a temperature that could be consistently referenced with then-modern technology, yeah. You’d have to control a lot of factors to make sure it’s not any hotter than it necessarily needs to be.
Uh… if you can get liquid water hotter than 100°C without adding other substances or pressure you should go claim your Nobel prize or wizard robe.
Today we casually say “100 °C at 1 atm,” but in Fahrenheit’s time, controlling or even measuring atmospheric pressure was hard. Boiling water on different days could still get different temperatures because the air pressure was different that day or at that location. They also only had alcohol-based thermometers, maybe some early mercury ones… it wasn’t easy to measure reliably.
Boiling point drops ~0.5 °C per 150 meters of elevation, or something to that effect. It was unreliable for big science when the goal is lab-friendly anchor points.
Boiling water is full of pockets of steam that may be higher than 100C, and will have cold spots too. It’s really not very easy at all to get any quantity of water to 100C stably and consistently throughout. Not easy enough to be a foundational reference, with the tools of a century or two ago. Boiling is also sensitive to altitude and pressure changes, and may be shifted slightly based on the mineral content of the water. It is in fact not dead simple.
No it won’t, who told you that? That’s not how thermodynamics works
Yes it will. Who told you it won’t? This is how thermodynamics works.
The second law?
Please explain how there can be a cold zone in boiling water, I’m dying to learn.
You think every molecule in a pot of boiling water is at exactly the same temperature? Of course there are variations throughout. You don’t need to invoke the fundamental laws of the universe to figure that out.