Yves here. This “news you can use” piece describes how animals, small children, and the elderly are particularly vulnerable to heat, how to recognize the signs, and what steps to take if you see signs of heat stress. It also lists some of the medications that increase the risk of hot temperature exposure.
By Jennifer Marlon, a senior research scientist at the Yale School of the Environment. Originally published at Yale Climate Connections
When temperatures soar, not everyone’s body handles the heat the same way – and for some, the risks can be severe.
Although heat waves threaten everyone, children, pets, and elderly family and friends face disproportionate dangers, each for distinct physiological reasons that every parent, pet-owner, and watchful friend should understand. And as climate change intensifies heat waves across the globe, understanding who faces the greatest risk – and how to help them – is a matter of life and death.
Children: Developing Systems Under Stress
Children’s bodies are fundamentally different heat-processing machines than those of adults. Their surface area-to-body weight ratio is much higher than ours, meaning they absorb heat from the environment more rapidly. Paradoxically, this same ratio should help them cool down faster – but their immature temperature-regulation systems can’t keep up with the demand.
Young children produce more metabolic heat per kilogram of body weight, yet their sweat glands are smaller and less efficient. They also have a higher core temperature threshold before sweating begins, essentially giving them a narrower margin of safety.
Infants face additional risks. Their kidneys are still developing, making them more susceptible to dehydration, while their larger heads and thinner skulls provide less protection for temperature-sensitive brain tissue.
Perhaps most critically, children depend entirely on adults for heat protection – they can’t recognize early heat stress symptoms, seek shade independently, or adequately hydrate themselves.
WHAT TO DO: Watch for signs like fussiness, decreased urination, or unusual lethargy, and immediately move children to cool environments while offering frequent small sips of water (or breast milk or formula for infants).
Pets: Silent Sufferers With Limited Cooling Options
Dogs and cats evolved different cooling mechanisms than humans, making them particularly vulnerable to our warming world. Dogs primarily cool through panting and limited sweating through their paw pads – far less efficient than human perspiration. Their normal body temperature runs two to three degrees higher than ours, giving them less buffer before dangerous overheating sets in.
Flat-faced, or brachycephalic, breeds such as pugs, bulldogs, and Persian cats face additional risks due to their shortened airways, which impede efficient panting. Dark-colored animals absorb more heat, while thick-coated breeds struggle to release it.
Unlike humans, pets can’t communicate their distress clearly or take protective actions like removing clothing or seeking air conditioning.
Ground temperature poses an often-overlooked threat. Asphalt can reach 150°F on a 90°F day, causing severe paw burns within seconds – a risk owners frequently underestimate because they’re wearing protective shoes.
WHAT TO DO: If you see your pet walking strangely, lifting paws repeatedly, or moving at an irregular pace, their paws may be burning. Immediately guide them onto grass, dirt, or into shade, and consider carrying small dogs on hot pavement. Devin Newman, a vet at Bush Animal Hospital in Eugene, Oregon, who is also my brother-in-law, says that if you cannot put your hand against the pavement for 10 seconds, then it’s too hot for a dog.
Don’t leave animals (or children!) in a hot car, even for a few minutes. Be mindful before breaking glass on someone else’s car, however, as some newer cars have a pet setting to keep dogs and cats comfortable.
Elderly: Aging Bodies, Diminished Defenses
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Aging brings multiple changes that reduce the body’s heat tolerance. As people age, their hearts pump less blood with each beat, making it harder for their cardiovascular system to move blood to the skin for cooling. Their sweat production declines, and their skin becomes thinner and less effective at temperature regulation.
Chronic conditions common in older adults – diabetes, heart disease, kidney problems – can make it harder for their bodies to stay cool. Many essential medications, including diuretics, beta-blockers, and antihistamines, interfere with the body’s natural cooling system or increase dehydration risk. Changes to a person’s memory and thinking patterns can make it harder to notice heat danger signs or know how to respond appropriately. Living alone may leave elderly individuals without help during dangerous heat events, while fixed incomes might force impossible choices between air conditioning and other necessities.
WHAT TO DO: Check on elderly relatives or neighbors daily during heat waves. Ensure they have access to air conditioning or cooling centers and help them identify early warning signs like dizziness, nausea, or confusion that warrant immediate cooling and medical attention.
The Climate Connection
These vulnerabilities matter more than ever because extreme heat events are becoming more frequent, intense, and prolonged. What were once rare heat waves are becoming regular summer occurrences, and previously safe temperatures are becoming dangerous when sustained over days. Understanding these distinct risk factors empowers us to protect our most vulnerable loved ones through targeted prevention – from never leaving children or pets in cars to ensuring elderly relatives have cooling plans and social check-ins during heat waves.
In our rapidly warming world, this knowledge isn’t just helpful – it’s essential for keeping our families safe.
As our esteemed correspondents from the Carolinas also note, the humidity has an important effect on how well our sweating cools our bodies. Sothron climes with high humidity will subtly increase the dangers of overheating by both masking absolute heat and decreasing the rate of heat exchange our skins can achieve.
Another aspect of high sweat rates is the loss of electrolytes via the sweat. People will become faint during high heat events through depletion of essential minerals, such as potassium, that happens when we sweat profusely. That is the secret to Gatoraid and related “sports drinks.” A football coach at the University of Florida asked faculty members at the Medical School to devise a solution to the dehydration effects his football players were experiencing. They discovered that if they fed his players a sweet drink loaded down with minerals, they performed better on hot days. Their solution was a solution.
Gatoraid: https://en.wikipedia.org/wiki/Gatorade
Stay safe, stay cool, in all its meanings.
A less palatable but much less costly, on a per-gram-dry-electrolyte basis, alternative to Gatorade or similar pre-mixed drinks is dry oral rehydration salts. I have been using “TriOral” brand for nearly a decade. Current price, in 100-pack size (each packet contains 7 grams of sodium and potassium salts, and 13 grams glucose, and makes 1 liter of electrolyte drink) is $0.40 per pack, up 1/3 since the beginning of the pandemic.
My trainer, who trained and rehabbed elite athletes (professionals, Olympic contenders, Division A participants) was part of a mafia of MDs who treated the same level of athlete and were fetishistic about reading studies.
They recommended against Gatorade pretty forcefully. It’s not better at hydrating than water. Its level of sugars offsets the electrolyte benefits.
This somewhat qualifies their take:
https://www.quora.com/Since-Gatorade-claims-to-hydrate-people-better-than-water-shouldnt-everyone-drink-gatorade-instead-of-water
When I was foresting in my prime, August was the toughest month. The humidity was worse than the heat, and it’s not getting better. Some hard-wrung wisdoms:
: Flux. We figured this out during the blizzard, 72′ inside and we were still freezing. The temperature difference twixt inner wall and outside, plus the wind convection, meant the temperature looked good but the walls were draining heat from us. Heat index 105 with 90% humidity and no wind over 5mph did the inverse this last week. Sous vide.
: Ice cold at the base of the skull cools the brain, held in hand cools the heart. I have an ice-yoke I take from the freezer and put around my neck, brisk at first but I can lean my arteries into it.
: Salts as a pick-me-up: one package of tangerine EmergenC mixed with a teaspoon of Pedialyte Berry Blast powder and you get something like Brawndo. It’s got Electrolytes!
If it is an option, planting shady trees around your home might be a good idea – so long as they are not an easily flammable type like Eucalyptus. The shade helps keep the heat off your home and if you have a good type of tree, you can feel a few degrees drop in temperature when underneath them. Like has been found with Covid, to combat the heat will probably require a layered defense starting with outside your home and working your way in until you reach your skin.
A drop of caution here. In the last two years we’ve had explosive growth. This morning I pinned up a Black Raspberry wand 13 feet long. That is enormous, over twice normal.
We’ve gone to coppicing heights with our trees. Hurricane force winds are new, some of the growth seems spindly, and the local silver maples launch wind sails from on high. Full size limbs on a roof is a really bad day.
You can similarly feel the temperature drop when you get neat to or enter parks with a lot of tree cover, like Central Park, or residential complexes with a lot of trees.