6 ms·
80% humidity with 35C+ heat means death within 15 minutes.
by elorant 5y ago
80% humidity with 35C+ heat means death within 15 minutes.
- tsjq 5y agothis is so common in coastal places in Southern India. no death in 15mins here.
- chromaton 5y agoI read stuff like this on HN and think that many of you must be living in a different physical reality.
- elorant 5y agoI 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 agoIt'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 agoYou'll be shocked to learn about steam rooms.
- amluto 5y agoI 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 agoAnd, like, the entire American south
- MomoXenosaga 5y agoIn 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 agoA 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 agoI've been in steam rooms. You're strongly advised to stay no longer than twenty minutes inside.
- meheleventyone 5y agoHere'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 agoIt is when people who don't have any real understanding of physics or biology make absurd comments.
- chromaton 5y agoReminds 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 agoWhy? 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 agoI totally agree that's correct except for key qualifying statement.
- andrewinardeer 5y agoDo you have a source on this please?
- xroche 5y agoIt's the wet bulb thermometer reading (temperature read by a thermometer covered in water-soaked cloth over which air is passed). At 35°C it is considered lethal for humans after a couple of hours. > Wet bulb thermometer readings are significantly lower than the more familiar dry bulb readings, which do not take humidity into account. Researchers say that at a wet bulb reading of 35C, the body can no longer cool itself by sweating and such a temperature can be fatal in a few hours, even to the fittest people. https://www.telegraph.co.uk/global-health/climate-and-people/hotter-human-body-can-handle-pakistan-city-broils-worlds-highest/ https://www.telegraph.co.uk/global-health/climate-and-people...
- Sanzig 5y agoThey're confusing it with a 35 C wet bulb temperature. 35 C dry bulb temperature would only equal 35 C wet bulb temperature at 100% RH. You can convert with a psychrometric chart [1] or with a calculator [2]. At sea level, 35 C dry bulb, 80% humidity is about 32 C wet bulb. Dangerously hot, yes, but it won't kill you in 15 minutes. [1] https://upload.wikimedia.org/wikipedia/commons/9/9d/PsychrometricChart.SeaLevel.SI.svg https://upload.wikimedia.org/wikipedia/commons/9/9d/Psychrom... [2] https://www.omnicalculator.com/physics/wet-bulb https://www.omnicalculator.com/physics/wet-bulb
- matwood 5y ago95F at 80% humidity is typical summer weather in the southeastern US (though it's been much cooler this year). Is it comfortable? No, but it's also not death in 15 minutes.
- theli0nheart 5y agoWhere does it get 95° F and 80% humidity in the southeastern US? I grew up in Miami, and it was rare to have a day above 90° F in the summer, but the humidity made it unbearable. I can’t even imagine how hot it would have felt at 95° F or higher with the same humidity—I wouldn’t be surprised if it was deadly.
- ericabiz 5y agoHouston.
- theli0nheart 5y agoJust as the OP said, these temperatures are deadly. From https://www.houstontx.gov/health/Epidemiology/e-heat-illness.html#:~:text=When%20temperatures%20rise%2C%20the%20risk,heat%2Drelated%20illnesses%20also%20increases.&text=Between%201979%20and%201999%2C%20heat,involving%20Houston%20residents%20were%20reported https://www.houstontx.gov/health/Epidemiology/e-heat-illness....: > In the summer of 2000, 26 deaths involving Houston residents were reported. In 2001, 13 deaths were due to heat. From https://environmenttexas.org/news/txe/global-warming-increase-heat-related-deaths-houston https://environmenttexas.org/news/txe/global-warming-increas...: > Thursday, September 6, 2007, HOUSTON – The death toll from extreme heat in Houston each summer will increase from about 24 to nearly 32, resulting in 192 additional heat-related deaths by mid-century
- eadmund 5y ago> Just as the OP said, these temperatures are deadly. > > Thursday, September 6, 2007, HOUSTON – The death toll from extreme heat in Houston each summer will increase from about 24 to nearly 32 The actual number of heat deaths in Houston and Harris County in 2018 was 15; Houston itself sees 4–6 per year. Maybe air conditioning is more common a decade later than was originally predicted, or perhaps medical intervention arrives more quickly or is more effective. Sources: https://nihhis.cpo.noaa.gov/Urban-Heat-Island-Mapping/Campaign-Cities-Detail?udt_7915_param_detail=4105 https://nihhis.cpo.noaa.gov/Urban-Heat-Island-Mapping/Campai... and https://www.houstonpublicmedia.org/articles/news/in-depth/2019/07/08/338761/houston-weather-forecasters-exploring-ways-to-improve-heat-warnings/ https://www.houstonpublicmedia.org/articles/news/in-depth/20...
- jolux 5y agoNo it doesn’t, that was pretty much the weather in Boston on Monday. It was pretty dreadful being out in it, but not deadly.
- bottlelion 5y agoCrazy that steam rooms exist then…
- Turbots 5y agoYou mean "wet bulb" temperature of 35 degrees, which is something different.
- dahfizz 5y agoWho knew that saunas are actually death chambers...
- petercooper 5y agoA sauna has extremely low humidity. A steam room, on the other hand..
- syoc 5y agoThis is not in line with the traditional sauna definition.
- elric 5y agoNot quite. There are dry saunas. And wet saunas. And everything in between. And then there are steam rooms. They are different things.
- webreac 5y agoSauna are dry. The wet ones are hammam.
- deleted 5y ago[deleted]
- Jommi 5y agoCompletely false. Traditional authentic Finnish (where sauna was invented) sauna is wet. Dry sauna is some weird American concoction.
- pope_meat 5y agoLaughs in slavic banya. You soft western babies with your dry saunas. Over there the banya is kept at 110% humidity, and old men beat you with sticks the whole time.
- amelius 5y agohttps://www.imdb.com/title/tt1877543/ https://www.imdb.com/title/tt1877543/
- MR4D 5y ago4 million people in Houston would beg to differ. I’m sure there are many other places as well.
- sharms 5y agoMy family and I were outside in above 35C and 80% humidity for over 8 hours two weeks ago and everyone was fine. Lots of walking etc with no issues.
- webreac 5y agoI can easily stay 15 minutes in a hammam. That is > 40°C and > 95% humidity. I think I have sometimes reached 30 minutes
- anthk 5y agoThen as a Basque I would die on some heat waves in August happening every decade or so.