Columbia Climate School: High Heat Is Preferentially Killing the Young, Not the Old, New Research Finds

[OKIsItJustMe]

https://news.climate.columbia.edu/2024/12/06/high-heat-is-preferentially-killing-the-young-not-the-old-new-research-finds/

High Heat Is Preferentially Killing the Young, Not the Old, New Research Finds
Kevin Krajick

December 6, 2024
Many recent studies assume that elderly people are at particular risk of dying from extreme heat as the planet warms. A new study of mortality in Mexico turns this assumption on its head: it shows that 75% of heat-related deaths are occurring among people under 35―a large percentage of them ages 18 to 35, or the very group that one might expect to be most resistant to heat.

“It’s a surprise. These are physiologically the most robust people in the population,” said study coauthor Jeffrey Shrader of the Center for Environmental Economics and Policy, an affiliate of Columbia University’s Climate School. “I would love to know why this is so.” The research appears this week in the journal Science Advances.

The researchers chose Mexico for the study because it collects highly granular geographical data on both mortality and daily temperatures. The researchers reached their conclusions by correlating excess mortality―that is, the number of deaths above or below the average―with temperatures on the so-called wet-bulb scale, which measures the magnified effects of heat when combined with humidity.

The analysis found that from 1998 to 2019, the country suffered about 3,300 heat-related deaths per year. Of these, nearly a third occurred in people ages 18 to 35―a figure far out of proportion with the numbers in that age bracket. Also highly vulnerable: children under 5, especially infants. Surprisingly, people 50 to 70 suffered the least amount of heat-related mortality.

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https://doi.org/10.1126/sciadv.adq3367

[BlueWaveNeverEnd]

1. maybe age 18 to 35 are more likely to work in the heat

[OKIsItJustMe]

2. Yes, that is one of the suggested explanations

However, notice children under 5, especially infants.

The researchers say several factors may be at work. Young adults are more likely to be engaged in outdoor labor including farming and construction, and thus more exposed to dehydration and heat stroke. The same goes for indoor manufacturing in spaces that lack air conditioning. “These are the more junior people, low on the totem pole, who probably do the lion’s share of hard work, with inflexible work arrangements,” said Shrader. Young adults are also more likely to participate in strenuous outdoor sports, the researchers point out. A previous separate analysis by Mexican researchers showed that death certificates of working-age men were more likely to list extreme weather as a cause than those of other groups.

[Mister Ed]

3. The higher infant mortality might be due to the fact that infants and toddlers lack the ability to perspire. n/t

[OKIsItJustMe]

5. Uh... Babies sweat

https://www.healthline.com/health/baby/sweaty-baby

Why Is My Baby Sweating?

Babies can sweat just like adults. And like adults, sweating may be caused by many things. If your baby is sweating, they may be hot. Try removing clothes or adjusting the room temperature. As with adults, sometimes sweating may mean a fever.

You’ve heard about hot flashes during menopause. And you had your fair share of hot spells during pregnancy. But did you know the sweats can happen at other stages of life, too? Even — get this — babyhood.

If your baby’s waking up hot and sweaty at night, you may be alarmed and wonder if it’s normal.

Rest assured: While sweating at night — or in the daytime, for that matter — can affect anyone of any age, sweating in newborns and babies is common.

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https://pmc.ncbi.nlm.nih.gov/articles/PMC6773238/

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Eccrine sweat glands

Eccrine glands were the first type of sweat gland discovered; as they were initially described in 1833 by Purkinje and Wendt and in 1834 by Breschet and Roussel de Vouzzeme, but were not named eccrine glands until almost 100 years later by Schiefferdecker [11]. Eccrine glands are often referred to as the small gland variety, but are by far the most ubiquitous type of sweat gland [12]. Humans have ~2–4 million eccrine sweat glands in total and are found on both glabrous (palms, soles) and non-glabrous (hairy) skin [13–15]. Gland density is not uniform across the body surface area. The highest gland densities are on the palms and soles (~250–550 glands/cm2) [16] and respond to emotional as well as thermal stimuli. The density of eccrine glands on non-glabrous skin, such as the face, trunk, and limbs are ~2–5-fold lower than that of glabrous skin [16], but distributed over a much larger surface area and are primarily responsible for thermoregulation.

The eccrine glands are functional early in life and, starting at ~2–3 years of age, the total number of eccrine glands is fixed throughout life [12–14]. Therefore, overall sweat gland density decreases with skin expansion during growth from infancy and is generally inversely proportional to body surface area. As a result, children have higher sweat gland densities than adults [11], and larger or more obese individuals have lower sweat gland densities than their smaller or leaner counterparts [13,17]. However, higher sweat gland density does not necessarily translate to higher sweating rate. In fact, most of the variability in regional and whole-body sweating rate within and between individuals is due to differences in sweat secretion rate per gland, rather than the total number of active sweat glands [18,19]. Eccrine sweat is mostly water and NaCl, but also contains a mixture of many other chemicals originating from the interstitial fluid and the eccrine gland itself. The structure and function of eccrine glands and the composition of eccrine sweat will be discussed in more detail in subsequent sections of this paper.

Apocrine sweat glands

The apocrine gland is a second type of sweat gland, which was first recognized by Krause in 1844 and later named by Schiefferdecker in 1922 [20,21]. Apocrine sweat glands are located primarily in the axilla, breasts, face, scalp, and the perineum [21,22]. As shown in Figure 1, these glands differ from eccrine glands in that they are larger and open into hair follicles instead of onto the skin surface [12]. In addition, although present from birth, the secretory function of apocrine glands does not begin until puberty [23]. Apocrine glands produce viscous, lipid-rich sweat, which is also comprised of proteins, sugars, and ammonia [21,23]. The function of apocrine glands in many species is generally regarded as scent glands involved in production of pheromones (body odor), although this social/sexual function is rudimentary in humans. Apocrine gland innervation is poorly understood, but isolated sweat glands have been found to respond equally to adrenergic and cholinergic stimuli [23].

Apoeccrine sweat glands

A third type of sweat gland, only recently described by Sato et al. in 1987 [23,24] is the apoeccrine gland. Apoeccrine glands develop from eccrine sweat glands between the ages of ~8 to 14 years and increase to as high as 45% of the total axillary glands by age 16–18 [23]. They are intermediate in size, but as the name suggests, apoeccrine glands share properties with both eccrine and apocrine glands. Like apoeccrine glands, apoeccrine glands are limited in distribution, as they are contained to only the axillary region. Apoeccrine glands are more similar to eccrine glands in that the distal duct connects to and empties sweat directly onto skin surface [23]. In addition, the apoeccrine gland produces copious salt water secretions similar to eccrine sweat [23]. The function of this secretion is unknown, but unlikely to play a significant role in thermoregulation since evaporation is inefficient in the axilla region. The innervation of the apocrine gland is still poorly understood, but in vitro models suggest the apocrine gland is more sensitive to cholinergic than adrenergic stimuli [23,24].

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One problem is that babies, being smaller than adults have a higher ratio of surface area to weight, so it is more difficult for them to regulate their body temperatures. (i.e. they get hotter in the heat, and colder in the cold.)

[Mister Ed]

7. Quite so. And you've identified the likely cause of the infant mortality at the end of your post:

One problem is that babies, being smaller than adults have a higher ratio of surface area to weight, so it is more difficult for them to regulate their body temperatures. (i.e. they get hotter in the heat, and colder in the cold.)

And honestly, I originally tried to type

"The higher infant mortality might be due to the fact that infants and toddlers lack the ability to regulate their body heat through perspiration. n/t"

but I shortened it because it wouldn't fit in the subject line.

[Escurumbele]

8. And engage in high activity sports while ignoring the high heat. At that age, most of us think

are Supermen/Superwomen.

[OKIsItJustMe]

9. And prior to that, there is no concept of mortality

https://apnews.com/article/high-school-football-heat-deaths-climate-change-2455ba5852d83f548754e44240abf99b

Hotter summers are making high school football a fatal game for some players

BY MICHAEL CASEY
Updated 5:51 PM EST, September 20, 2024

BRANDON, Mississippi (AP) — Soon after Ashanta Laster reached the hospital, she was ushered into the emergency room where she saw doctors performing CPR on her teenage son.

Laster had gotten a call that 17-year-old Phillip Laster Jr., a lineman who played for a top Mississippi high school, had collapsed on the field during an August 2022 practice. At the time, the family says the heat index was 102 degrees (38.9 degrees Celsius) on the football field.

“They kept compressing his chest trying to bring him back. No response, no response. Never a heartbeat,” said Laster, recalling how she dropped her purse, called her husband and started praying.

“I said I was going to call all the prayer warriors and bring my son back. I wanted him to come back,” she continued. “At that point, it was just an unbelievable moment. I can’t believe my son was gone. I could not believe it ... I was in a state of shock ... that he died ... at football practice.”

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[mucifer]

4. That is not consistent with the 1995 heat wave in Chicago that

killed over 500 people in 4 days. It was mostly elderly and poor people. More Black people died than Hispanic people. Since then Chicago implemented cooling centers all over the city and wellness checks for the elderly. Personally, I think what helps is you can buy a wall unit AC for $100 and put it in a small room and the cost to run it is way less than in 1995.

Here are some articles about the heat wave. People 18-25 were not the ones who more often died then. So there may be a difference in Mexico and Chicago that is. not accounted for culturally.

https://pmc.ncbi.nlm.nih.gov/articles/PMC1380980/#:~:text=RESULTS%3A%20In%20July%201995%2C%20there,deaths%20and%20739%20excess%20deaths.

https://www.scientificamerican.com/article/chicago-learned-climate-lessons-from-its-deadly-1995-heat-wave1/

[OKIsItJustMe]

6. You know... things change

Very early on in COVID-19 (before lockdowns) my dental hygienist said that at Thanksgiving Dinner, a relative who is a doctor, warned that this new disease would likely be hardest on young children. I replied that the data from China suggested otherwise.

Time has borne that out.

https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-in-babies-and-children/art-20484405

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How likely is it for a child to become sick with coronavirus disease 2019 (COVID-19)?

Data tracking between 2020 and 2023 found that children made up about 18% of all people with reported COVID-19 in the United States.

While children are as likely as adults to catch the virus that causes COVID-19, kids are less likely to become seriously ill. From 2020 to the end of March 2024, children up to age 17 accounted for about 1.5% of people who needed to be treated for COVID-19 in the hospital.

But some children with COVID-19 need to be hospitalized, treated in the intensive care unit or placed on a machine to help them breathe, called a ventilator. Very rarely, COVID-19 can cause death.

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