4 ms·

I read stuff like this on HN and think that many of you must be living in a different physical reality.

elorant 5y ago
I live in Greece where currently we're in the middle of a heatwave (temperatures above 38C for more than a week). I don't recall a single time in my life where we had high temperatures and high humidity levels. But I've read once that if the temperature is higher than 35C and the humidity above 60% you can't live outside because the body can't expel heat fast enough.
- lucozade 5y ago
  > But I've read once It's best not to assume what you read on the internet is always true. Some people post things that turn out to be utter nonsense. Easily checkable nonsense to boot.
  - elorant 5y ago
    It's explained further down in the comments. It's the so called wet bulb temperature. I was wrong about the 15 minutes limit though, turns out it's about two hours.
- chromaton 5y ago
  You'll be shocked to learn about steam rooms.
  - amluto 5y ago
    I believe that steam rooms are incompatible with human life in the sense that you will overheat and eventually in a hot steam room. Most people are sensible and exit before this happens.
  - fisherjeff 5y ago
    And, like, the entire American south
    - MomoXenosaga 5y ago
      In fairness it was air conditioning that turned Florida into useless swamp to tourist paradise/trap. I really hate it because I know it will only make things worse long term but my North European country is rapidly installing AC everywhere now thanks to increasing heatwaves.
      - taylodl 5y ago
        A great positive feedback loop, no? Anthropogenic Climate Change (ACC) creates a need for more AC which in turn creates more ACC which furthers the need for more AC. Yeah I don't see this going well for the next few decades.
  - elorant 5y ago
    I've been in steam rooms. You're strongly advised to stay no longer than twenty minutes inside.
- meheleventyone 5y ago
  Here's the science behind this claim: https://advances.sciencemag.org/content/6/19/eaaw1838 https://advances.sciencemag.org/content/6/19/eaaw1838 > While some heat-humidity impacts can be avoided through acclimation and behavioral adaptation (12), there exists an upper limit for survivability under sustained exposure, even with idealized conditions of perfect health, total inactivity, full shade, absence of clothing, and unlimited drinking water (9, 10). A normal internal human body temperature of 36.8° ± 0.5°C requires skin temperatures of around 35°C to maintain a gradient directing heat outward from the core (10, 13). Once the air (dry-bulb) temperature (T) rises above this threshold, metabolic heat can only be shed via sweat-based latent cooling, and at TW exceeding about 35°C, this cooling mechanism loses its effectiveness altogether. Because the ideal physiological and behavioral assumptions are almost never met, severe mortality and morbidity impacts typically occur at much lower values—for example, regions affected by the deadly 2003 European and 2010 Russian heat waves experienced TW values no greater than 28°C (fig. S1). In the literature to date, there have been no observational reports of TW exceeding 35°C and few reports exceeding 33°C (9, 11, 14, 15). The awareness of a physiological limit has prompted modeling studies to ask how soon it may be crossed. Results suggest that, under the business-as-usual RCP8.5 emissions scenario, TW could regularly exceed 35°C in parts of South Asia and the Middle East by the third quarter of the 21st century (14–16).
boringg 5y ago
It is when people who don't have any real understanding of physics or biology make absurd comments.
- chromaton 5y ago
  Reminds me of the comment that a 40 MPH car crash isn't potentially deadly: https://news.ycombinator.com/item?id=26470848 https://news.ycombinator.com/item?id=26470848
EVa5I7bHFq9mnYK 5y ago
Why? 15 min is a bit of an artistic stretch, but otherwise the statement above is correct. 35C at 80% humidity means wet bulb temperature of 32 degrees, which is not survivable by most humans. 38C at 80% humidity means TW of 35 degrees, which is not survivable by anyone.
- chromaton 5y ago
  I totally agree that's correct except for key qualifying statement.

I live in Greece where currently we're in the middle of a heatwave (temperatures above 38C for more than a week). I don't recall a single time in my life where we had high temperatures and high humidity levels. But I've read once that if the temperature is higher than 35C and the humidity above 60% you can't live outside because the body can't expel heat fast enough.

lucozade 5y ago
> But I've read once It's best not to assume what you read on the internet is always true. Some people post things that turn out to be utter nonsense. Easily checkable nonsense to boot.
- elorant 5y ago
  It's explained further down in the comments. It's the so called wet bulb temperature. I was wrong about the 15 minutes limit though, turns out it's about two hours.
chromaton 5y ago
You'll be shocked to learn about steam rooms.
- amluto 5y ago
  I believe that steam rooms are incompatible with human life in the sense that you will overheat and eventually in a hot steam room. Most people are sensible and exit before this happens.
- fisherjeff 5y ago
  And, like, the entire American south
  - MomoXenosaga 5y ago
    In fairness it was air conditioning that turned Florida into useless swamp to tourist paradise/trap. I really hate it because I know it will only make things worse long term but my North European country is rapidly installing AC everywhere now thanks to increasing heatwaves.
    - taylodl 5y ago
      A great positive feedback loop, no? Anthropogenic Climate Change (ACC) creates a need for more AC which in turn creates more ACC which furthers the need for more AC. Yeah I don't see this going well for the next few decades.
- elorant 5y ago
  I've been in steam rooms. You're strongly advised to stay no longer than twenty minutes inside.
meheleventyone 5y ago
Here's the science behind this claim: https://advances.sciencemag.org/content/6/19/eaaw1838 https://advances.sciencemag.org/content/6/19/eaaw1838 > While some heat-humidity impacts can be avoided through acclimation and behavioral adaptation (12), there exists an upper limit for survivability under sustained exposure, even with idealized conditions of perfect health, total inactivity, full shade, absence of clothing, and unlimited drinking water (9, 10). A normal internal human body temperature of 36.8° ± 0.5°C requires skin temperatures of around 35°C to maintain a gradient directing heat outward from the core (10, 13). Once the air (dry-bulb) temperature (T) rises above this threshold, metabolic heat can only be shed via sweat-based latent cooling, and at TW exceeding about 35°C, this cooling mechanism loses its effectiveness altogether. Because the ideal physiological and behavioral assumptions are almost never met, severe mortality and morbidity impacts typically occur at much lower values—for example, regions affected by the deadly 2003 European and 2010 Russian heat waves experienced TW values no greater than 28°C (fig. S1). In the literature to date, there have been no observational reports of TW exceeding 35°C and few reports exceeding 33°C (9, 11, 14, 15). The awareness of a physiological limit has prompted modeling studies to ask how soon it may be crossed. Results suggest that, under the business-as-usual RCP8.5 emissions scenario, TW could regularly exceed 35°C in parts of South Asia and the Middle East by the third quarter of the 21st century (14–16).

boringg 5y ago

It is when people who don't have any real understanding of physics or biology make absurd comments.

chromaton 5y ago
Reminds me of the comment that a 40 MPH car crash isn't potentially deadly: https://news.ycombinator.com/item?id=26470848 https://news.ycombinator.com/item?id=26470848

EVa5I7bHFq9mnYK 5y ago

Why? 15 min is a bit of an artistic stretch, but otherwise the statement above is correct. 35C at 80% humidity means wet bulb temperature of 32 degrees, which is not survivable by most humans. 38C at 80% humidity means TW of 35 degrees, which is not survivable by anyone.

chromaton 5y ago
I totally agree that's correct except for key qualifying statement.