Reduced inflammation from cold plunges lacks scientific support

Cold water swimming can induce positive stress

The tradition of cold water swimming (or taking a cold plunge, or even a cold shower) has been shown to release the same hormones triggered during a stress response. This can have the effect of increasing blood flow, improved mental acuity, and more.

Some data shows cold showers can help with depression

An icy water exposure can lead to the release of norepinephrine, cortisol, dopamine, and other stress hormones that are beneficial, among other potential effects. Some data shows that this type of exposure can help combat depression symptoms among some patients, but more research is still needed. (Some users may encounter a paywall.)

Heatstroke treatment guidelines were built almost exclusively on research in men

Protocols for the standard treatment recommendation for heatstroke—whole-body cold water immersion—were built based on studies almost entirely in men. The research wasn't replicated in women, who typically cool faster than men during cold water immersion, raising questions about standard protocol safety for women, due to the risk of overcooling.

Partial freezing results from trying to freeze water while preventing expansion

Within a sealed container, partial freezing of water increases the contained volume and the pressure, preventing further freezing without decreasing the temperature further. Once cooled below -23 degrees Celsius (-9.4 degrees Fahrenheit), an uncommon type of ice that contracts as it forms is produced, facilitating the complete freezing of the contained water.

Wind chill speeds up the loss of heat from the body

During cold weather conditions, strong winds against exposed skin can produce a sensation of temperature colder than the surrounding air temperature. The accelerated loss of body heat increases the risk of frostbite and hypothermia, with frostbite able to set in as quickly as five minutes.

Heat-related complications are of greater concern for distance runners than cardiac threats

Analysis of more than 130,000 runners in Tel Aviv events during a seven-year period indicated that the runners were 10 times more likely to experience heatstroke than serious cardiac problems. Scientists suggest that runners should take 10 to 14 days to acclimate to a hot climate before tackling a serious run.

Certain medications that affect blood flow or mood boost the risk of heatstroke

Drugs that narrow blood vessels, beta blockers that regulate blood pressure, diuretics, antidepressants, and antipsychotics can all affect the body's ability to regulate its internal body temperature, and so individuals taking these medications need to take special care in extreme heat and when exercising in hot conditions.

Why hibernating bears don't get blood clots

For mammals, long periods of inactivity can lead to health problems—blood flow slows and pools, veins kink and distort, and clots potentially form. Hibernation takes this risk to the extreme, yet for decades why animals like bears did not exhibit...

A history of treating frostbite

Amid Napoleon's invasion of bitterly cold Russia, soldiers succumbed to frostbite by the thousands. Nineteenth century doctors recommended walking and rubbing snow around the affected area. Fast forward to recent years, and the FDA has approved its first ever drug to treat frostbite. Listen to this podcast to learn the history of this wintry affliction.

Bath bombs can produce endothermic reactions that cool water

In bath bombs containing citric acid and sodium bicarbonate, water facilitates the reaction between the bicarbonate and acid, providing energy as the salt dissolves. The loss of energy in the water reduces the average speed of the water molecules, reducing the temperature of the bath.

Cold-blooded reptiles seek heat, and that behavior may help combat fungal infections

This Radiolab podcast episode takes on the idea that though our human bodies are too warm for the majority of fungal species to effectively replicate inside our bodies, that's not the case for reptiles. Yet when those species warm their bodies by basking in the sun on rocks, they can soak up heat and may also help keep fungal infections in check.

How specialized oxygen mixtures like heliox enable deep diving without feeling drunk

Beyond a depth of about 30 meters (98 feet), if divers are breathing surface air, which is about 78% nitrogen, underwater pressure forces more nitrogen into the bloodstream and induces nitrogen narcosis, whose symptoms resemble alcohol intoxication. Through saturation diving, where nitrogen is replaced with helium—an inert gas—deep divers can maintain cognitive function while working for extended periods.

Listen to why extensive ear rinsing can create problems

The clinician who hosts this podcast discusses how his patient developed swimmer's ear after he flooded his ears with water during his daily showers, ostensibly to clean them. The resulting itchy, painful ears were the result of removing protective earwax in the ear and also altering the typical pH of the ear.

The benefits of extreme pain rituals, explained

We naturally avoid pain and see it as a negative experience. But many traditional cultures incorporate extremely painful rituals into their religious ceremonies, claiming they, in fact, provide ample benefits. Researchers were able to observe boosts in happiness and a sense of belonging in a tribe of Mauritians after they undertook a rigorously painful religious ritual. Read about the study here.

Interest in intermittent fasting outpaces the science

The public interest in fasting diets has outpaced the science behind related health claims. This article details how the science of fasting diets is mainly exploratory and focused on longevity and disease prevention. Current findings suggest fasting kick-starts regenerative processes in the body, decreases inflammation, and improves health outcomes overall. However, much of this research focuses on the short-term impact of fasting.

Pooping or puking out pathogens is sometimes recommended with food poisoning

Sometimes stopping food poisoning-linked diarrhea with over-the-counter medications is a bad idea because it may prolong illness. Doctors can advise you if your diarrhea or vomiting is severe about what medications to take and when, but generally doctors recommend trying to stay hydrated during a bout of food poisoning and letting the body naturally remove pathogens from the body via vomiting or diarrhea, as needed.

'Blackout challenge' can cause brain damage or death in under 5 minutes

A social media trend that encourages viewers to asphyxiate themselves until they lose consciousness in the hopes of feeling "high" or euphoric has garnered the interest of teens and adolescents, with dangerous results. Variations of this deadly challenge have been adolescent trends every few years.

Extreme grief elevates cardiovascular risk and lowers immune system function

A 2014 analysis of cardiovascular risk and bereavement after a lost partner found that grief elevates the risk of stroke and heart attack for the 30 days following death of a partner and the risk then attenuates after that.

Surgery before the dawn of anesthesia

The arc toward anesthetics was painfully slow, with early pain mitigation offerings ranging from analgesics—drugs that dim pain but don't block it—and numbing surgical sites with cold water to gassing patients with carbon dioxide or bashing or bleeding them unconscious. Such treatments and the torturous surgery they preceded led many to avoid even life-saving procedures, and those who survived often kept silent about the trauma.

Over time, people develop a resistance to spicy foods

TRPV1 is a receptor in the body that detects potentially harmful things and responds in a variety of ways, including sweating, tearing up or a runny nose. Over time, more exposure to spicy foods can build up a resistance that minimizes these reactions.

Kava, kratom, St. John's Wort, and green tea extract present health concerns

Consumer Reports, which tests supplements for safety, urges consumers to avoid these four supplements due to safety warnings from researchers and public health authorities.

Search for psychrotolerant and psychrophilic microorganisms found in Antarctica

Developed following a five-week expedition to the southern continent, "Life Under the Ice" allows users to examine a petri-dish-like microscopic world and uncover recordings of organisms that can withstand, or even thrive, in the harsh environment.

The world's largest waterfall is in the ocean

In the Denmark Strait between Greenland and Iceland, a series of cataracts descend from 2,000 to 10,000 feet beneath the surface. The underwater waterfall is possible because cold water is denser than warm water and quickly sinks in the region.

An avowed rationalist discusses his near-death experience

Documentarian Sebastian Junger, a veteran reporter and skeptic discusses his experiences—in particular, a frightening vision—after an aneurysm and internal hemorrhaging left him nearly dead. Junger talks about his NDE, the possible scientific explanations, and how that day changed his fundamental worldview.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

New evidence suggests the eruption's victims died as their blood boiled

While most Pompeii victims suffocated or were crushed, spectroscopic analysis of bones from a nearby town indicates something more extreme: exposure to superheated gas that instantly boiled blood and caused deadly internal trauma.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Poison ivy's rash-causing compound is found in the plant's roots, stem, and leaves—so coming into contact with any part of the plant can lead to rashes for the 85% of people who are allergic to it.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.