The emergence of heat and humidity too severe for human tolerance (2020) • Hacker News Board

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#181

Post by baybal2 » Wed, Aug 11, 2021, 10:12 AM UTC

stormbrew wrote: post #32

trhway wrote: post #22

Earlier quoted context omitted.

No, it wouldnt work as the heat would have nowhere to go. And the mid east people didn't do it - https://en.m.wikipedia.org/wiki/Windcatcher Instead you build and live in highrise/towers - that gives cheap ventilation which is a half the solution. And I liked the siesta and the following it very active life till deep night in Spain - another natural adaptation to hot climate. It makes for much calmer and steady life…

> Instead you build and live in highrise/towers I mean, I'm sure this is valid in some places but having lived in high rises relatively far north in Canada let me tell you it is very possible (and in my experience very common) to build high rises that retain heat so well they basically bake the occupants in high heat/humidity. I doubt most of North America's high rise apartment buildings above some latitude are parti…

Look no further than Dubai how to build highrises with good feat insulation, and cooling.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#182

Post by raxxorrax » Wed, Aug 11, 2021, 10:32 AM UTC

poorjohnmacafee wrote: post #147

ghshephard wrote: post #67

Earlier quoted context omitted.

Having lived in Singapore for five years (2012-2017) (and worked out in the field for about 50% of that time) I can say that Singapore is one of the milder places to live. It never ever gets particularly hot (I genuinely can't recall a 100+ degree day in the entire time I was there), and the humidity, while, "sticky" is never really extreme. The thing that gets to you is that the climate never seems to change (with t…

> I can say that Singapore is one of the milder places to live. It never ever gets particularly hot Singapore is almost exactly on the equator. UV readings get up to 11 each day (extreme), whereas the most I ever saw in say SF was 5. Your experience is one experience, mine is that it's a sauna every day of the year. I've experienced extremely hot days in terms of subjective experience of WBT as explained in article.…

But it is also close to the ocean which is usually much more livable than anywhere inland in Malaysia or Indonesia.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#183

Post by darkerside » Wed, Aug 11, 2021, 10:40 AM UTC

masklinn wrote: post #71

boplicity wrote: post #2

Kim Stanley Robinson's recent book The Ministry For the Future starts with a very disturbing scenario: A heatwave with a "web bulb" temperature of 35 Celsius. It turns out, in those temperatures, even young and healthy people can't survive. Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die. It's looking increasingly likely that such heatwaves are possible in t…

> It turns out, in those temperatures, even young and healthy people can't survive. Of note: that’s literal, even doing nothing and sitting in front of a fan you can’t cool down. And do one of the issues 35 WBT “hides” is that any activity lowers the heat stress threshold. Sugarcane workers are already dying due to heat stress today, and have been for a while. There’s been an “epidemic” of “kidney disease” in central…

At that heat, counterintuitively, sitting in front of a fan will only heat you up faster.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#184

Post by krisoft » Wed, Aug 11, 2021, 10:44 AM UTC

lmilcin wrote: post #177

I see a lot of uninformed people on this thread thinking 35C wet bulb temperature isn't such a big deal and proposing various ineffective tips to cool down. Let me explain what the issue is, in simple words: WET BULB TEMPERATURE IS NOT TEMPERATURE YOU SEE ON A THERMOMETER. (please, don't nitpick, I am aware of wet bulb thermometers) Wet bulb temperature is combination of temperature and humidity. The simple layman wa…

> please, don't nitpick, I am aware of wet bulb thermometers

I don’t want to nitpick. Everything you wrote is correct as far as I know. I only want to add to it.

I think understanding what a wet bulb thermometer is crucial to understand the term. And it is a very simple thing: you take a totally normal thermometer, you put it in the shade. So far everything is normal, this is how you measure air temperature since forever. You then put a little sock on the end of the thermometer and make it wet. Super simple. On a traditional mercury thermometer the end is a little glass sphere where the mercury is stored. This glass sphere is called the “bulb”. A wet bulb thermometer is just a thermometer where the bulb is wet. Super simple.

Why would you do this? Obviously this “wet bulb” thermometer will measure a lower temperature than the dry one. This is because evaporation of the water takes away energy from the thermometer. The faster the water can evaporate bigger the difference you will see between the dry and the wet thermometers. If the air is saturated with water vapor then the two measurements will be the same. If the air is dry you will have lots of evaporation and the wet bulb will be way colder than the dry one. So if all you have is two thermometers a sock and a bucket of water you can measure the relative humidity in this indirect way by comparing the two temperatures.

An other way to think about a wet bulb thermometer is that it is a very crude modell of a sweating human. You keep the sock wet and that simulates the thermometer sweating. The temperature the termometer reaches is the limit of temperature you can cool yourself down using evaporative cooling.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#185

Post by fighterpilot » Wed, Aug 11, 2021, 10:46 AM UTC

shadilay wrote: post #99

throwaway894345 wrote: post #50

It’s wild to me that even the Biden administration appears so cavalier on climate. $1.2T on infrastructure and a follow up $3.5T budget bill and in both the environmental provisions are lame. Still no carbon pricing or anything that might make Exxon execs too uncomfortable (yes, I know Exxon supports carbon pricing in public because they don’t think anyone will actually do it).

While it's great and all for america to invest in the environment at the end of the day america is still only a small part of the world. The issues of climate are global in nature and unlikely to be solved in my lifetime.

The US needs to be leading on this issue. They're the largest economy and have benefited the most out of everyone (on a per-capita basis) from the carbon pollution that they're causing, leaving the poorer and hotter countries in the global south to bear the brunt of the downside a century later.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#186

Post by darkerside » Wed, Aug 11, 2021, 10:49 AM UTC

Where can you find historical wet bulb temperatures for a specific locality?

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#187

Post by fighterpilot » Wed, Aug 11, 2021, 10:54 AM UTC

jfoutz wrote: post #163

trashtester wrote: post #135

Earlier quoted context omitted.

According to this Lancet study, about 5M die from cold globally, annually, while about 500K die from heat: https://www.thelancet.com/journals/lanplh/article/PIIS2542-5... I found the article through this link: https://news.emory.edu/stories/2021/07/climate_change_heat_r... Interestingly, the emory link did not quote how many deaths were due to cold vs heat, but it did say that cold related deaths were going down and…

That's good stuff! I peeked at the lancet study, but it didn't support my trollish response to the OP. The real point I was trying to make was the crazy extremes, the higher variance. I vividly recall running one morning when it got to -40F/-40C the night before. It sucked. The house was cold, work was cold. But one day is just a freak thing we all deal with, like snow in Atlanta. I remember a lot of government build…

If the ratio is 10:1, then even if you have increasing variance (which is bad), an increase in the mean may offset that badness. I can't comment beyond that, I'm just talking generally about distributions with two fixed cutoffs at both extremes (beyond which = death or high likelihood of death).

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#188

Post by lmilcin » Wed, Aug 11, 2021, 10:57 AM UTC

krisoft wrote: post #184

lmilcin wrote: post #177

I see a lot of uninformed people on this thread thinking 35C wet bulb temperature isn't such a big deal and proposing various ineffective tips to cool down. Let me explain what the issue is, in simple words: WET BULB TEMPERATURE IS NOT TEMPERATURE YOU SEE ON A THERMOMETER. (please, don't nitpick, I am aware of wet bulb thermometers) Wet bulb temperature is combination of temperature and humidity. The simple layman wa…

> please, don't nitpick, I am aware of wet bulb thermometers I don’t want to nitpick. Everything you wrote is correct as far as I know. I only want to add to it. I think understanding what a wet bulb thermometer is crucial to understand the term. And it is a very simple thing: you take a totally normal thermometer, you put it in the shade. So far everything is normal, this is how you measure air temperature since for…

Yes, this is completely correct.

I would add the wet bulb thermometer needs large evaporation area (so the sock cannot be too wet and definitely you can't put it in the bucket) and/or some airflow around it. Otherwise it will show some temperature between actual dry bulb and wet bulb temperatures.

In practice, nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It is easier to just measure dry bulb temperature and humidity separately and then look up wbt in a table.

In general measuring temperatures correctly is a tricky business, what with temperature gradients in the objects you try to measure and the thermometer itself. I just recently needed to explain to a bunch of people why there is no such thing as "temperature in the sun" and that you can pick any temperature between WBT and around 5800K and it is going to be a correct temperature "in the sun" depending on properties and shape of the object you are trying to measure..

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#189

Post by stevekemp » Wed, Aug 11, 2021, 11:00 AM UTC

jiggawatts wrote: post #143

boplicity wrote: post #2

Kim Stanley Robinson's recent book The Ministry For the Future starts with a very disturbing scenario: A heatwave with a "web bulb" temperature of 35 Celsius. It turns out, in those temperatures, even young and healthy people can't survive. Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die. It's looking increasingly likely that such heatwaves are possible in t…

> Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die. That's an exaggeration. Extreme heat (including heat waves that exceed this threshold) happen semi-regularly, and the death rate when they occur is nowhere near 100%. More like 0.1% or less. Electrically-powered air conditioning is not the only way to cool a human body. Simply escaping to an underground or s…

The problem with lots of people in water is that leads to drownings.

"There is a clear connection between heat and drowning. That's when people want to go in or near the water, and the risks of drowning increase," FSL's Executive Director Kristiina Heinonen told Yle in July:

https://yle.fi/uutiset/osasto/news/drowning_deaths_reach_10-...

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#190

Post by dalbasal » Wed, Aug 11, 2021, 11:03 AM UTC

jiggawatts wrote: post #143

boplicity wrote: post #2

Kim Stanley Robinson's recent book The Ministry For the Future starts with a very disturbing scenario: A heatwave with a "web bulb" temperature of 35 Celsius. It turns out, in those temperatures, even young and healthy people can't survive. Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die. It's looking increasingly likely that such heatwaves are possible in t…

> Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die. That's an exaggeration. Extreme heat (including heat waves that exceed this threshold) happen semi-regularly, and the death rate when they occur is nowhere near 100%. More like 0.1% or less. Electrically-powered air conditioning is not the only way to cool a human body. Simply escaping to an underground or s…

Well... people are resourceful. I mean, we may have gotten soft living in civilisation... but we still have some survival instinct. Shade, bathing, burrowing etc.

Still, that factoid is troubling. These are conditions that exceed humans' operating conditions. We're used to that on the cold side. Plenty of people thrive (miserably) in places that get cold.

But, there are actually far fewer good cooling options. Air conditioning is more complicated than heating. You can heat with fire, warm clothes. Even exercise, though this is not sustainable. A sauna is nice, but people don't live in their saunas until temperatures get tolerable.

Also, the heat cutoff is more of a universal. A lot of organisms seem to start failing at temperatures like this.