Here's the short version:
Wet-bulb weather is when, because of a combination of humidity and heat, you can't naturally cool off with things like sweat.
There are certain combinations where the weather only needs to be 25.8C for a health younger person, or 21.9C for an elderly person for "wet-bulb" to be achieved.
Climate change is real, and it's causing more instances of "wet-bulb" weather.
Outside activities may not be possible in the summer in certain parts of the world, people will die, the rich will move.

[–] would_be_appreciated@lemmy.ml 64 points 2 months ago (2 children)

Wet-bulb weather is when, because of a combination of humidity and heat, you can’t naturally cool off with things like sweat.

This isn't quite right, even though the gist of it ends up being right. This is one of very few things I'm legitimately an expert in, so I don't want to let it go uncorrected not because it makes a big difference, but because it just feels weird not to and maybe somebody will be interested.

Dry bulb temperature is what you typically read when you're looking at a thermometer. The bulb, the thing that's checking the temperature, is literally dry. To get a wet bulb reading, you essentially put a wet sock around a thermometer (to get a "psychrometer") and swing it around for a while, because you get a different reading when the water is evaporating off it. So when the air is fully saturated (100% humidity, standing in a cloud), your wet bulb and dry bulb readings will be the same. In all other cases, your wet bulb temperature will be lower.

"Wet bulb weather" isn't really a phrase people use. High wet bulb, high relative humidity, high absolute humidity - all the same thing (and in fact, if you have just one of those and the dry bulb temperature, you can calculate the others). They just measure how wet the air is in slightly different ways.

[–] whostosay@lemmy.world 16 points 2 months ago

i was interested, thank you.

[–] podperson@lemm.ee 3 points 2 months ago

I appreciate the precision AND pedantry of your response. Great, concise explanation of exactly what that term means.

[–] CyberMonkey404@lemmy.ml 22 points 2 months ago (4 children)

only needs to be 25.8C for a health younger person, or 21.9C for an elderly person

That's disturbingly low

[–] admin@lemmy.haley.io 22 points 2 months ago* (last edited 2 months ago) (1 children)

It’s also at 100% humidity in case that wasn’t clear.

Edit: ok so what he posted wasn’t wrong but the study said that it could be as low as that for some groups of people. For the average person it’s almost 10 degrees C higher which is lower than it used to be.

However for heat sensitive people (not sure what that means) it can be disturbingly low

[–] idiomaddict@lemmy.world 3 points 2 months ago (1 children)

So it’s more like ~35C, but it used to be 40? Is that because of constant heat exposure? Like, is my heat tolerance better in the winter?

[–] admin@lemmy.haley.io 6 points 2 months ago

It seems like it used to be 35° but now it’s ~34°.

I don’t have access to the actually study but I would hypothesize that it’s likely because we are seeing more studies about things like this and as we collect more data that’s changing these values to be closer to what we see in the real world.

[–] frightful_hobgoblin@lemmy.ml 1 points 2 months ago

so are my morals

[–] Petter1@lemm.ee 1 points 2 months ago

Meaning you can kill elderly people if you set up air humidifier everywhere 😮🤔 even at normal 22C

[–] whostosay@lemmy.world 0 points 2 months ago (2 children)

can we get these temperatures in freedom degrees?

[–] Courantdair@jlai.lu 1 points 2 months ago* (last edited 2 months ago)

Depends on the articulation, but I'd say at most 6

[–] idiomaddict@lemmy.world 0 points 2 months ago

25.8, 21.9

Divide by 5, multiply by 9, and add 32.

roughly 78.5 and 71.5

[–] adespoton@lemmy.ca -2 points 2 months ago (1 children)

So… only slightly related to the headline?

Headline was obviously false from the start, but it turns out it was just clickbait?

[–] DerisionConsulting@lemmy.ca 10 points 2 months ago (1 children)

Not clickbait at all.

Wet-bulb is the combination of heat and humidity, and it is deadly in 6 hours. The article is about the first time they have lab tested the conditions on humans to determine the exact numbers, instead of just using the 35C estimate that we have been using.

[–] adespoton@lemmy.ca 1 points 2 months ago (2 children)

The headline here has no mention of wet bulb?

“For the first time, humans were subjected to a deadly combination of heat and humidity.”

The article is about the first formalized test measuring the relationship between heat and humidity on thermal management in the body, mostly using a single fit thirty year old male. It’s not about how the first human subjected to wet bulb conditions handled them, but about an improved understanding of the relationship of heat and humidity on thermal management of humans.

[–] shapesandstuff 2 points 2 months ago (1 children)

Wet bulb is an effect thats based on heat and humidity. Which part is confusing you? /g

[–] adespoton@lemmy.ca 1 points 2 months ago (1 children)

The part where the headline is supposedly about the first time humans have experienced it?

The content is fine… the formatting and headline are atrocious.

[–] shapesandstuff 1 points 2 months ago

Ahh gotcha, yeah thats a bit clickbaitey. I read it as "for the first time in a controlled experiment"