• fearout@kbin.social
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    1 year ago

    Reposting my comment from another similar thread ‘cause I think it’s kind of important to add.

    Ok, so it doesn’t mention wet bulb temperature anywhere, so I went to figure it out. The first thing I was surprised with is apparently most of online calculators don’t take in values higher than 50C.

    I couldn’t find the exact data about humidity for that day, but it has been 35-40%+ at a minimum for most days in that region, sometimes even reaching 90%.

    So, 52C at around 40% humidity is 37.5C in wet bulb temp. The point of survivability is around 35, and most humans should be able to withstand 37.5 for several hours, but it’s much worse for sick or elderly. 39 is often a death sentence even for healthy humans after just two hours — your body can no longer lose heat and you bake from the inside. That’s like having an unstoppable runaway fever. And with that humidity it’s reached at 54C.

    We’re dangerously close to that.

    • eek2121@lemmy.world
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      1 year ago

      An absolute death sentence for folks without air conditioning or another means to stay cool.

      • fearout@kbin.social
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        1 year ago

        It’s a bit different depending on your health and all that. But 35 WBT is a definite point for everyone (since our bodies run at 36–37C). Kinda like the difference between “some will die” and “most will die”.

        • beigeoat
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          1 year ago

          I mean to say that the wet bulb temperature at which most will die is ~31.5°C, the gaurdian report I linked is saying that the 35°C number comes from a 2010 study, whereas the findings of the 2022 study found the number to be much lower ~31.5°C.

          • fearout@kbin.social
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            1 year ago

            It’s probably a measure for persistent temperature then. Like, if you lock someone in a room at that temperature (or if it wouldn’t cool down at night, for example), then that person would be dead no matter what after some amount of hours or days.

            35 is more of a real-life guideline, since it does cool down at night and you don’t need to withstand this temperature persistently and indefinitely.

            And for the last several years there have been lots of places that exceeded 31.5 WBT during the day. Hell, you can probably find several places with that WBT right now. But since people don’t drop dead immediately and need time to heat up, it’s still survivable.

            Think about it in terms of a 2D graph. You need to know the duration in addition to temperature to gauge survivability. A million degrees is survivable for a femtosecond, 35 for an average earth day, and ~31 indefinitely.

        • PeleSpirit@lemmy.world
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          1 year ago

          From @beigegat’s article it says that from real expieriences it’s 31.5C

          The oft-cited 35C value comes from a 2010 theoretical study. However, research co-authored by Kenney this year found that the real threshold our bodies can tolerate could be far lower. “Our data is actual human subject data and shows that the critical wet-bulb temperature is closer to 31.5C,” he says.

        • Aux@lemmy.world
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          1 year ago

          If that was true, people would die in Russian sauna - 80-90° at 100% humidity with 10-20 minute sessions.

          • fearout@kbin.social
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            1 year ago

            Well, people do die in saunas. More often than you might think. And those who can sit through 20 minutes are usually already accustomed to them, it’s not like people can sit for a long time the first time. Stick an unprepared elderly person there and it’s often not going to end well.

            Also, right after intense sauna sessions (and in between as well) people dunk themselves into very cold plunge pools or snowdrifts to quickly cool off.

            And you got the temperature/humidity ratios wrong. 100% humidity is used in a hammam, a Turkish-style steam room, and those are kept at around 45-55C. Russian saunas never exceed 90%, most are kept at around 70%.

            Have you been to one and looked at the hydrometer? It’s really hard to raise the humidity above 70–80%, and the usual for most people 1-2 ladles per ~10 mins barely raises the humidity above 60%.

    • Crucible_Fodder
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      1 year ago

      Yeah, that makes me think that data was just wrong. Every homeless in the area would be dead with those temps and humidities.

      • cley_faye@lemmy.world
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        1 year ago

        Homeless have been dying during summer and winter for years. It’s just, as with too many things, the new normal and not newsworthy. If they started dying from critical weather I’m not sure we would even know.

      • ChickenLadyLovesLife@lemmy.world
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        1 year ago

        Every homeless in the area would be dead with those temps and humidities.

        Shhhh … don’t give the elites running our planet another reason to ignore global warming.

    • AstroKevin@lemmy.world
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      1 year ago

      I don’t want to be rude, and I completely am all for combating climate change, but 39C is not baking your insides…

      I have been deployed to multiple places that were 52C (~125F) in the day/night with high humidity levels, in full long sleeve/pants for 8 hours at a time. 39C (~102F) is hot, but not bake you from the inside type of hot.

      Elderly and sick are people not included in what I said above for obvious reasons.

      • fearout@kbin.social
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        1 year ago

        I find it pretty funny that people are arguing both “35 WBT is pretty fine” and “31.5 WBT is a death sentence”.

        Yet somewhere in that range seems to be the consensus for an actual “your body is on the clock and you’re not surviving it for a prolonged time” situation.

        I don’t know your personal experience and how dangerous it was in regards to temperature, but high temperature environments start feeling pretty humid at like ~50%, so you still pretty much need an actual temperature/humidity reading to gauge it correctly.

        So guys, take it to the scientists :) I’m not talking out of my ass here, rather quoting research data. There are a couple dozen papers listed in the link above, and most seem to agree on the dangerous temp region. Read their methodology and reasoning if you’re interested to learn more.

        • AstroKevin@lemmy.world
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          1 year ago

          Oh I’m not arguing it’s a hot temp and exerting yourself in those temps is very much a death sentence; especially without water. I’m saying that many people in the world have lived through those temperatures. Research studies have a way of making things a bit more dire than what is normally human survivable, probably for legal/medical moral reasons.

          The US military definitely has rules against 40+ WBT and state how many hours of work per hours of rest we could have in high temp+humidity levels. However, I, and anyone who had to deploy or live in East Africa (like Djibouti) or the Middle East can definitely attest, 50WBT is survivable for 8 hours days. Again, not talkin’ elderly or sick persons.