Jun 29Liked by Katelyn Jetelina

I saw these incredibly important tidbits in yesterday’s Nature Briefing (on 6/28/23), and felt that this information about safe, simple, effective ways to cool down should get much wider attention. (Doesn't look like I can include links - sorry!)

Podcast: the smart way to stay cool

For a shortcut to relief in hot weather, immerse your hands in cool water, biologist Craig Heller tells a Scientific American podcast. The hairless skin on our palms, soles and upper face contain special blood vessels — arteriovenous anastomoses (AVAs) — that offer a more direct connection to the core of the body, bypassing the delicate capillaries. Gently cooling this skin helps you to chill out fast — but avoid freezing-cold water, which will cause the AVAs to slam closed. What not to do: use ice or a wet towel on the back of your neck. You’ll be misleading your brain’s thermostat, which uses the temperature of this area to trigger your body’s natural cooling methods.

Science, Quickly podcast | 11 min listen or 8 min read

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The coldest summer of the rest of your life.

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That info on heat stroke from the CDC is not great. At face value, it seems to suggest that fans are sufficient to provide cooling. However, this is definitely *not* the case if the victim's skin is dry, unless they've been moved somewhere quite cool (not just "cooler").

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But here in Fascist-ville, we not have a law that says local municipalities (read that to mean the liberal cities such as Austin, San Antonio, Houston and Dallas) cannot circumvent various state regulations and are forbidden to mandate work/water breaks for outdoor workers in this heat and humidity.

These are probably the same members of the Lege (also known as the National Laboratory for Bad Government...thank you to the late Molly Ivins) and the Gov and Lt. Gov who proudly proclaim themselves the "best" Christians.

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A very important heads up. I'm seeing some smoke related stuff in the office this week. The CO2 in my house is about 1000 ppm today because it's otherwise a lungful of humid irritants when I open the windows. I've been spraying several bottles of Febreze "Serene Vanilla Sunrise" into the air daily, what a difference.


Does anyone else get the sense that we are frogs in a kettle, being slowly brought to boil?

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I had a severe head trauma injury five years ago this August (I died eleven times — I thank our gear cardiac care unit at MaineMed for finally stabilising me) and one of the interesting lasting effects of that is I don’t sweat. Ever.

My apartment is eighty one degrees right now with a sixty degree humidity which I find utterly comfortable. Not a drop of sweat anywhere. I actually have to be careful outside because it can hit the nineties with high humidity and I don’t know it’s that dangerous.

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In addition to hydration, electrolyte replacement is also important when humans are sweating for prolonged periods. Sweat varies from 1/7 to 1/2 "Normal" saline depending on the person's acclimation and the sweat rate (Journal of Applied Physiology 103:990). "Sports Drinks" are glorified Kool-Aid. Home brew recipes with NaCl and KCl are searchable. I personally aim for ~1/3 normal saline with 10 mEq KCl with this recipe:

1/2 tsp NaCl + Scant 1/8 tsp KCl / liter water

Can Add 1-2 TBSP sugar for taste preferences

Use non iodinated salt for taste

Lime and Lemon juice to taste

Usual disclaimer:

If you are on any medications that influence sodium and potassium talk to your provider

Do not confuse this chat room with medical advice

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In case you like to visualize


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Sheesh. Somebody might think that political views would give way to health and good sense. I know, I know, that was just a silly thing to say. Thanks for this alert and especially the chart about signs of heat illness.

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Please use a map that includes Canada, since most (NOT all) of the wildfire smoke comes from there.

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You mention hydrate with water but not Gatorade. Your CDC chart recommends sports drinks. A study was done at a couple of marathons where water stations were set every km at one. Every 5 km at another. Post event hyponatremia was significantly higher where there were more water stations. While the CDC chart states to avoid salt tablets, it encourages sports drinks. (Personally, I do not consider Red Bull a sports drink, but I am sure there are plenty who disagree with me.). I was under the impression a good bit of study went into the Gatorade formulation. Univ of FL. If this is wrong you can give me (an AL resident) another reason to be a Gator-hater (sports talk).

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As always, a super helpful article! I wanted to propose a topic for a future article: indoor air quality. There is all this emerging literature on how dangerous pollution is (outdoor and indoor) and how it contributes to all kinds of health conditions. Other than the emerging trend of switching from gas to electric in the home, and solving the massive problem of pollution, I’m curious if we should all have HEPA filters at home and if so what kind and how to pick? I wonder if it’s good for us to be breathing filtered air which might remove pollution, or if we take out all the allergens too, are we setting ourselves up for autoimmune disease or other problems? Thanks for considering!

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Hi Katelyn, Thank you for all of your professional information, it is so appreciated.

I listened to the UCSF grand rounds and heard you are paying attention to waste water stats. I wondered if you could mention how to access those ( I am in Orange County Calif. and my Mom, who’s 100 and just tested positive is in Ct.) I think there is an East Coast uptick?

Thank you again and take good care.

Warm regards, Lynn Gaylord

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During the pandemic we were asked to

- Forego high quality masks so that "front line" workers could have them but wear cloth masks primarily for source control

- Postpone "non-essential" medical care

- "Wait our turn" to get vaccinated

In other words a lot of the "asks" were appeals to altruism.

I'm concerned about how this will translate into more acute health emergencies related to severe heat and smoke. Will some people be asked *not* to run their air conditioners and/or air purifiers? Will high quality masks be rationed once again? What happens when water starts running low? Is giving everybody what might otherwise be sound survival advice tenable when resources are scarce? There be dragons.

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chatGPT says -

On average, a breathing human exhales approximately 1 kilogram of carbon dioxide (CO2) in a 24-hour period. This value can vary depending on factors such as body size, metabolism, activity level, and environmental conditions. It's important to note that the carbon dioxide exhaled by humans is a result of the body's natural respiration process and is not considered a significant contributor to overall greenhouse gas emissions or climate change.


Ahmmm, yes, but there are 9 Billion of us....

To convert kilograms to metric tons, you divide the number of kilograms by 1,000.

9 billion kilograms is equal to 9,000,000,000 kilograms.

To convert this to metric tons, you divide 9,000,000,000 by 1,000:

9,000,000,000 kg ÷ 1,000 = 9,000,000 tons

Therefore, 9 billion kilograms is equivalent to 9 million metric tons.

Every day.

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This is the perfect storm...of heat, humidity and here comes the smoke. Viewing the whole Earth with NASA's satellite images ( https://worldview.earthdata.nasa.gov ) shows the severity, range, and sources of wildfire smoke. So, KJ, could you sum up current evidence for long-term health effects from even moderately smoky air? Heat domes can be smoke pots, and it may be the jet stream's response to our unevenly warming world. Workers outdoors are at risk in their years to come while fire-fighters feel the worst of it immediately.

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