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> CDC recommends not using a fan at temperatures above 32.2°C I don't know quite how to put this, but are they idiots? I don't quite mean that, but at the very

> CDC recommends not using a fan at temperatures above 32.2°C I don't know quite how to put this, but are they idiots? I don't quite mean that, but at the very least there's something weird going on. I double down on this as they double down on their recommendation at the end of the article. Go to places like India, and see how people use fans, in the humid places like Kolkata and the dry places like Hyderabad. Fans obviously provide great relief at far higher temperatures than their 90°F. The very idea of suggesting not to use fans from such a low temperature is, to me who grew up in Melbourne, Australia and now lives in Hyderabad: ludicrous. Even when they talk about "people who are less able to cope with heat", it sounds like they may be giving advice very harmful to normal people, for the possible but highly contested safety of a few. —— When talking about ineffectiveness of fans in high temperature low humidity (which is Hyderabad summer to a tee—it barely gets below CDC's 90°F, and is very dry), the details mentioned make me sceptical of the entire approach of the studies. I know each time I've come to India, it's taken me well over a week to adjust to the temperature. (I still sweat more than most Indians do, but not as much as a day or two after I come.) And hydration is a rather important factor too, likely not accounted for adequately. We're talking definite heat stress circumstances, you can't expect to get accurate results from an unacclimated body. Yes, I am a layman casting doubt on the work of experts without investigating carefully. I imagine they've been at least somewhat careful about these things, none of these people will be idiots. It's probably not all as bad as the vibes I'm getting. Do treat my scepticism with scepticism of your own.

Clubber 2y ago
>> CDC recommends not using a fan at temperatures above 32.2°C >I don't know quite how to put this, but are they idiots? I can't believe they said that. They need to move anywhere in the US Southern region. 32.2C is a cool day reprieve in a Southern summer and fans are a necessity. https://baltimoreaircoil.com/evaporative-cooling#:~:text=As%20perspiration%20evaporates%20it%20absorbs,resulting%20in%20a%20cooler%20liquid https://baltimoreaircoil.com/evaporative-cooling#:~:text=As%....
- chrismorgan 2y ago
  Follow the link in the article. They do actually say explicitly that, with no tempering statements.
grugagag 2y ago
Absolutely. Fans help evaporate sweat off the skin accelerating the sweating cycle.
crop_rotation 2y ago
I think this might be meant for an audience for which the choice is not between fan and no fan, but fan and some other cooling mechanism (an AC). If you can use an AC, definitely prefer that at such temperatures. If the American population had to face hot and humid climate like that of North India, there will be an uproar and some big central solution pushed very quickly.
- crazygringo 2y ago
  If you follow the links, it's not. It's between fan and no fan. The supposed reason is the additional heating via convection that takes place.
dyauspitr 2y ago
I don’t get it either. I haven’t read the article but it always feels like a fan increases the rate at which my sweat evaporates, making me noticeably cooler. This was in the Middle East where in the shade temperatures easily go above 45C/113F in the summer
cassianoleal 2y ago
I'm 100% with you. I grew up in a place where winters can be fairly chilly - 0-10℃-ish, but in the summer it can go easily over 40℃. Fans are an absolute necessity. Classrooms without fans mean kids sleeping in class due to overheating. Being at home without a fan is an absurd notion (unless you have AC, of course). Go out in a hot day when the air is mostly still, and feel the relief every time the smallest breeze flows by. Skin has natural heatsinks, especially sweat. Blow air onto them and their efficiency multiplies. We should all know this - we put big fans atop CPU/GPU heatsinks for a reason.
didgeoridoo 2y ago
> The dueling conclusions underscore the tricky balance facing public health agencies, says Kristie Ebi, a heat epidemiologist at the University of Washington. “The messaging needs to be simple,” she says—but not too simple. It’s the COVID garbage all over again. They think the public are absolute drooling morons who cannot be trusted with any nuance, and they bake this prejudice into their recommendations. Good lord, we are never going to be able to rebuild trust in our institutions if they haven’t learned any lessons over the last 5 years.
- hn_throwaway_99 2y ago
  > They think the public are absolute drooling morons who cannot be trusted with any nuance I don't know where you've been the past couple years, but I think that's a fairly safe assumption.
  - kindatrue 2y ago
    This link should be mandatory reading for everyone who thinks the general public aren't drooling morons: https://awrestaurants.com/blog/aw-third-pound-burger-fractions https://awrestaurants.com/blog/aw-third-pound-burger-fractio... tldr: America fast food restaurants don't offer 1/3rd pound burgers because the general public knows that 3 < 4
  - kcplate 2y ago
    You know, I might be dumb as a stump, but I am pretty sure I can tell if a fan makes me feel cooler on a hot day…and if an expert tells me I am wrong, I’m going to ignore them.
- trhway 2y ago
  > the public are absolute drooling morons "They" aren't aliens. "They" come from that same public, and are as much drooling morons as the rest of the public (what i frequently remind to the Russians who whine about the Russian government). >to rebuild trust in our institutions will see how appointment of Kennedy Jr. as the health services tzar would work here :) Popular thinking among the Russian opposition is that the way Western societies reacted to Covid demonstrated to Putin the loss by those societies and by their institutions of the ability to act reasonably. And the inept reaction to the war in Ukraine seems to confirm that.
RiverCrochet 2y ago
This reminds me of a social studies teacher I had all the way back in like 1993. It was hot in the classroom and students would make paper fans and fan themselves. The teacher told us that the motion actually generates more heat and makes you hotter. He was right technically of course - 30 students waving something will probably heat up a windowless classroom a degree or two - but it still felt much better to have the air movement. The room I'm in now does get hot, and a fan pointing inward with one closed window doesn't help me feel more comfortable, but if I open 2 windows and have a fan pointing outward to create a current, it's great. Fans can blow hot air in an enclosed space and be unhelpful.
hn_throwaway_99 2y ago
Before discounting it, I think the article has some very interesting, non-obvious conclusions. Fundamentally that, in humid conditions, fans are more effective at higher temperatures, while in drier conditions, since most of the sweat on you will already have evaporated away, fans in dry environments are only useful up to a lower temp, as after that they act like a convection oven. The article did mention some studies spritzed participants with water, but didn't seem like they tested it across all possible conditions. Seems like spritzing yourself with water even in a dry environment would make a fan still a benefit at higher temps, given the proposed explanations in the article.
- chrismorgan 2y ago
  I don't discount it entirely, but as I remarked, I'm sceptical of that entire methodology, because it doesn't sound like they've controlled for acclimation, which experience says has a significant effect, and because the result itself is (perhaps consequently?) surprising.
GeoAtreides 2y ago
yet another comment calling experts idiots. I so wish people would be open to acknowledge that other people might know more about a subject than them anyway. using the magic of google I found: >Use fans, but only if indoor temperatures are less than 90°F. In temperatures above 90°F, a fan can increase body temperature. https://www.cdc.gov/heat-health/about/index.html https://www.cdc.gov/heat-health/about/index.html further searches led to: >under the hot and dry conditions, however, the fans increased body temperature, the strain on the heart, and thermal discomfort. In other words, the fans worked better at higher heat index temperatures. >There’s a physiological explanation: When air temperature soars above skin temperature, then the exchange of air between the body and the air switches; rather than dissipating away from the body, heat from the hotter air starts to flow into the body. https://time.com/5644737/fans-can-make-you-hotter/ https://time.com/5644737/fans-can-make-you-hotter/ which cites this study: Nathan B. Morris, Timothy English, Lily Hospers, et al. The Effects of Electric Fan Use Under Differing Resting Heat Index Conditions: A Clinical Trial. Ann Intern Med.2019;171:675-677. doi:10.7326/M19-0512 Searching the doi on google scholar reveals the stuyd, published in 2019, has 75 citations so far
- thegrim33 2y ago
  You linked to the very paper the article is about, which is referenced in the fourth sentence of the article, indicating you didn't spend a single second reading the article before commenting.
  - GeoAtreides 2y ago
    at least i didn't call the experts idiots
ivewonyoung 2y ago
I've lived in Hyderabad for more than the first two decades of my life without air conditioning and then moved to the US living in Texas and then the north east. I 100% agree with your sentiment, fans work even at 110F.

Clubber 2y ago

>> CDC recommends not using a fan at temperatures above 32.2°C >I don't know quite how to put this, but are they idiots? I can't believe they said that. They need to move anywhere in the US Southern region. 32.2C is a cool day reprieve in a Southern summer and fans are a necessity. https://baltimoreaircoil.com/evaporative-cooling#:~:text=As%20perspiration%20evaporates%20it%20absorbs,resulting%20in%20a%20cooler%20liquid https://baltimoreaircoil.com/evaporative-cooling#:~:text=As%....

chrismorgan 2y ago
Follow the link in the article. They do actually say explicitly that, with no tempering statements.

grugagag 2y ago

Absolutely. Fans help evaporate sweat off the skin accelerating the sweating cycle.

crop_rotation 2y ago

I think this might be meant for an audience for which the choice is not between fan and no fan, but fan and some other cooling mechanism (an AC). If you can use an AC, definitely prefer that at such temperatures. If the American population had to face hot and humid climate like that of North India, there will be an uproar and some big central solution pushed very quickly.

crazygringo 2y ago
If you follow the links, it's not. It's between fan and no fan. The supposed reason is the additional heating via convection that takes place.

dyauspitr 2y ago

I don’t get it either. I haven’t read the article but it always feels like a fan increases the rate at which my sweat evaporates, making me noticeably cooler. This was in the Middle East where in the shade temperatures easily go above 45C/113F in the summer

cassianoleal 2y ago

I'm 100% with you. I grew up in a place where winters can be fairly chilly - 0-10℃-ish, but in the summer it can go easily over 40℃. Fans are an absolute necessity. Classrooms without fans mean kids sleeping in class due to overheating. Being at home without a fan is an absurd notion (unless you have AC, of course). Go out in a hot day when the air is mostly still, and feel the relief every time the smallest breeze flows by. Skin has natural heatsinks, especially sweat. Blow air onto them and their efficiency multiplies. We should all know this - we put big fans atop CPU/GPU heatsinks for a reason.

didgeoridoo 2y ago

> The dueling conclusions underscore the tricky balance facing public health agencies, says Kristie Ebi, a heat epidemiologist at the University of Washington. “The messaging needs to be simple,” she says—but not too simple. It’s the COVID garbage all over again. They think the public are absolute drooling morons who cannot be trusted with any nuance, and they bake this prejudice into their recommendations. Good lord, we are never going to be able to rebuild trust in our institutions if they haven’t learned any lessons over the last 5 years.

hn_throwaway_99 2y ago
> They think the public are absolute drooling morons who cannot be trusted with any nuance I don't know where you've been the past couple years, but I think that's a fairly safe assumption.
- kindatrue 2y ago
  This link should be mandatory reading for everyone who thinks the general public aren't drooling morons: https://awrestaurants.com/blog/aw-third-pound-burger-fractions https://awrestaurants.com/blog/aw-third-pound-burger-fractio... tldr: America fast food restaurants don't offer 1/3rd pound burgers because the general public knows that 3 < 4
- kcplate 2y ago
  You know, I might be dumb as a stump, but I am pretty sure I can tell if a fan makes me feel cooler on a hot day…and if an expert tells me I am wrong, I’m going to ignore them.
trhway 2y ago
> the public are absolute drooling morons "They" aren't aliens. "They" come from that same public, and are as much drooling morons as the rest of the public (what i frequently remind to the Russians who whine about the Russian government). >to rebuild trust in our institutions will see how appointment of Kennedy Jr. as the health services tzar would work here :) Popular thinking among the Russian opposition is that the way Western societies reacted to Covid demonstrated to Putin the loss by those societies and by their institutions of the ability to act reasonably. And the inept reaction to the war in Ukraine seems to confirm that.

RiverCrochet 2y ago

This reminds me of a social studies teacher I had all the way back in like 1993. It was hot in the classroom and students would make paper fans and fan themselves. The teacher told us that the motion actually generates more heat and makes you hotter. He was right technically of course - 30 students waving something will probably heat up a windowless classroom a degree or two - but it still felt much better to have the air movement. The room I'm in now does get hot, and a fan pointing inward with one closed window doesn't help me feel more comfortable, but if I open 2 windows and have a fan pointing outward to create a current, it's great. Fans can blow hot air in an enclosed space and be unhelpful.

hn_throwaway_99 2y ago

Before discounting it, I think the article has some very interesting, non-obvious conclusions. Fundamentally that, in humid conditions, fans are more effective at higher temperatures, while in drier conditions, since most of the sweat on you will already have evaporated away, fans in dry environments are only useful up to a lower temp, as after that they act like a convection oven. The article did mention some studies spritzed participants with water, but didn't seem like they tested it across all possible conditions. Seems like spritzing yourself with water even in a dry environment would make a fan still a benefit at higher temps, given the proposed explanations in the article.

chrismorgan 2y ago
I don't discount it entirely, but as I remarked, I'm sceptical of that entire methodology, because it doesn't sound like they've controlled for acclimation, which experience says has a significant effect, and because the result itself is (perhaps consequently?) surprising.

GeoAtreides 2y ago

yet another comment calling experts idiots. I so wish people would be open to acknowledge that other people might know more about a subject than them anyway. using the magic of google I found: >Use fans, but only if indoor temperatures are less than 90°F. In temperatures above 90°F, a fan can increase body temperature. https://www.cdc.gov/heat-health/about/index.html https://www.cdc.gov/heat-health/about/index.html further searches led to: >under the hot and dry conditions, however, the fans increased body temperature, the strain on the heart, and thermal discomfort. In other words, the fans worked better at higher heat index temperatures. >There’s a physiological explanation: When air temperature soars above skin temperature, then the exchange of air between the body and the air switches; rather than dissipating away from the body, heat from the hotter air starts to flow into the body. https://time.com/5644737/fans-can-make-you-hotter/ https://time.com/5644737/fans-can-make-you-hotter/ which cites this study: Nathan B. Morris, Timothy English, Lily Hospers, et al. The Effects of Electric Fan Use Under Differing Resting Heat Index Conditions: A Clinical Trial. Ann Intern Med.2019;171:675-677. doi:10.7326/M19-0512 Searching the doi on google scholar reveals the stuyd, published in 2019, has 75 citations so far

thegrim33 2y ago
You linked to the very paper the article is about, which is referenced in the fourth sentence of the article, indicating you didn't spend a single second reading the article before commenting.
- GeoAtreides 2y ago
  at least i didn't call the experts idiots

ivewonyoung 2y ago

I've lived in Hyderabad for more than the first two decades of my life without air conditioning and then moved to the US living in Texas and then the north east. I 100% agree with your sentiment, fans work even at 110F.