8 Science-Backed Tips to Keep Your Feet From Burning on Hot Sand

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iStock

With temperatures hitting record highs this summer, beaches—and their promise of cool ocean dips—beckon. But to reach the waves, it's likely you'll first have to cross an expanse of foot-scalding sand. Sand is made up of decomposed rock—quartz, mostly, but also calcite, feldspar, gypsum, or basalt, sometimes with a smattering of shell, coral, or fish poop tossed in—and according to Paul Jarvis, a geologist and volcanologist at the University of Geneva, it receives solar energy via the process of radiation. The composition of sand causes it to heat up as the day progresses and to retain that heat, reaching temperatures as high as 140°F—sufficient to inflict third-degree burns. Here are tips for protecting your soles from this painful outcome.

1. WEAR THE RIGHT KIND OF SHOES.

This seems obvious, but the level of protection you get depends on the kind of shoe you're wearing. Materials such as plastic and rubber (what many soles are made of), foam resin (the stuff of Crocs), and the neoprene base of the Sand Socks that many beach volleyball players swear by provide a barrier between skin and sand. This helps cut down on conduction—the transfer of heat from the warmer surface of the sandy beach to the cooler surfaces of your feet. As a result, your feet are protected (at least temporarily) from blistering. And though they're likely the first shoes you picture when you think of the beach, flip-flops and other open shoes should be avoided on especially scorching days, because they let the hot sand in.

2. MAKE A PATH USING A COUPLE OF BEACH TOWELS.

Forgot your shoes in the car? You can protect your feet by rolling out a couple of towels to step on, repeating the process until you reach your coveted beach spot. The cotton of your towel is better at quelling heat transfer to your feet than the rubber soles of your shoes are due to what scientists call a lower thermal conductivity—“the measure of how fast heat can be conducted through the material,” Jarvis tells Mental Floss. However, your towel is also thinner than your shoe bottoms, and heat conducts faster through thin objects. In other words, you’ll have to hurry if you want to keep your feet cool.

3. RUN FAST …

The less time the soles of your feet spend touching the sand, the less time there is for conduction. But sprinting is probably a technique best reserved for covering short distances or for morning beach visits, before the sand has had a chance to soak up the solar rays for several hours and achieve maximum temperature. Because no matter how fast you run, conduction is still happening, and after some strides, your feet will eventually begin to feel the burn.

4. … OR BURROW YOUR FEET.

If you're loaded down with a cooler and tote bags, try a technique favored by professional beach volleyball players: Burrowing your tootsies as you walk, which puts your feet in contact with the much cooler sand beneath the surface. Because there are large gaps between grains of sand, it's “unable to efficiently transmit heat … through the sand bed to [its] deeper levels,” Jarvis says. So dig in a few inches. This way of “walking” is actually more of a slow shuffle, but it'll get you to your destination sans burns.

5. WET THE SAND …

It takes five times as much solar energy to heat water 1°C (33.8°F) as it does to heat sand by the same amount (what's technically known as heat capacity). So “adding just a small amount of water to the sand can dramatically increase the amount of heat the sand surface needs to receive before it gets hot,” Jarvis says. You can replicate the effect by toting a bucket of water and tossing its contents under your feet little by little as you go. While not the easiest method, it could be a solution for when you're already near the water and have to, say, run to the restroom or buy a snack. Just grab one of the kids' sand-castle buckets. Wet sand is also a lot less arduous to walk and run on than dry sand.

6. … OR YOUR FEET.

American pro beach volleyball player Sara Hughes has a go-to sand strategy: “To cool down, I personally like to put water on my feet,” she told USA Volleyball's blog. According to Jarvis, because water has a higher heat capacity than human skin, having wet—and therefore colder—feet means "you can be exposed to the beach for longer before your skin reaches a temperature at which it will burn.” Obviously, this is a highly temporary solution, since your feet will quickly dry. So bring the bucket for this tactic too: You might have to dip your feet into the water several times before reaching your ultimate destination.

7. FOLLOW THE SHADE.

Since it doesn’t take a lot of energy to change the temperature of sand, areas in shadow will feel noticeably cooler to the touch. It's easier to find those spots early in the morning or at the onset of evening, when the Sun is at an angle to the beach; the rest of the day, keep an eye out for shadowed spots made by the lifeguard chair, beach umbrellas, or palm trees to give your feet relief.

8. FIND A LIGHT-COLORED BEACH.

Should you opt to go shoe-less, choose your sand wisely. The heat capacity of the sand on any beach you visit is dependent on what minerals it’s comprised of—a challenge to know unless you do your own scientific studies, beach by beach. However, a general rule of thumb is that hotter beaches come with darker sands—and the opposite is also true. “Light-colored sand reflects, as opposed to absorbs, a significant proportion of the Sun’s radiation,” Jarvis says. “Dark sand, such as that originating from volcanic rocks [like basalt], is much more heat absorbent, meaning it will heat up quicker and therefore, potentially become much hotter.”

A Dracula Ant's Jaws Snap at 200 Mph—Making It the Fastest Animal Appendage on the Planet

Ant Lab, YouTube
Ant Lab, YouTube

As if Florida’s “skull-collecting” ants weren’t terrifying enough, we’re now going to be having nightmares about Dracula ants. A new study in the journal Royal Society Open Science reveals that a species of Dracula ant (Mystrium camillae), which is found in Australia and Southeast Asia, can snap its jaws shut at speeds of 90 meters per second—or the rough equivalent of 200 mph. This makes their jaws the fastest part of any animal on the planet, researchers said in a statement.

These findings come from a team of three researchers that includes Adrian Smith, who has also studied the gruesome ways that the skull-collecting ants (Formica archboldi) dismember trap-jaw ants, which were previously considered to be the fastest ants on record. But with jaw speeds of just over 100 miles per hour, they’re no match for this Dracula ant. (Fun fact: The Dracula ant subfamily is named after their habit of drinking the blood of their young through a process called "nondestructive cannibalism." Yikes.)

Senior author Andrew Suarez, of the University of Illinois, said the anatomy of this Dracula ant’s jaw is unusual. Instead of closing their jaws from an open position, which is what trap-jaw ants do, they use a spring-loading technique. The ants “press the tips of their mandibles together to build potential energy that is released when one mandible slides across the other, similar to a human finger snap,” researchers write.

They use this maneuver to smack other arthropods or push them away. Once they’re stunned, they can be dragged back to the Dracula ant’s nest, where the unlucky victims will be fed to Dracula ant larvae, Suarez said.

Researchers used X-ray imaging to observe the ants’ anatomy in three dimensions. High-speed cameras were also used to record their jaws snapping at remarkable speeds, which measure 5000 times faster than the blink of a human eye. Check out the ants in slow-motion in the video below.

14 Facts About Celiac Disease

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iStock.com/fcafotodigital

Going gluten-free may be a modern diet trend, but people have been suffering from celiac disease—a chronic condition characterized by gluten intolerance—for centuries. Patients with celiac are ill-equipped to digest products made from certain grains containing gluten; wheat is the most common. In the short-term this can cause gastrointestinal distress, and in the long-term it can foster symptoms associated with early death.

Celiac diagnoses are more common than ever, which also means awareness of how to live with the condition is at an all-time high. Here are some things you might not know about celiac disease symptoms and treatments.

1. Celiac an autoimmune disease.

The bodies of people with celiac have a hostile reaction to gluten. When the protein moves through the digestive tract, the immune system responds by attacking the small intestine, causing inflammation that damages the lining of the organ. As this continues over time, the small intestine has trouble absorbing nutrients from other foods, which can lead to additional complications like anemia and osteoporosis.

2. You can get celiac disease from your parents.

Nearly all cases of celiac disease arise from certain variants of the genes HLA-DQA1 and HLA-DQB1. These genes help produce proteins in the body that allow the immune system to identify potentially dangerous foreign substances. Normally the immune system wouldn't label gliadin, a segment of the gluten protein, a threat, but due to mutations in these genes, the bodies of people with celiac treat gliadin as a hostile invader.

Because it's a genetic disorder, people with a first-degree relative (a sibling, parent, or child) with celiac have a 4 to 15 percent chance of having it themselves. And while almost all patients with celiac have these specific HLA-DQA1 and HLA-DQB1 variations, not everyone with the mutations will develop celiac. About 30 percent of the population has these gene variants, and only 3 percent of that group goes on to develop celiac disease.

3. Makeup might contribute to celiac disease symptoms.

People with celiac disease can’t properly process gluten, the protein naturally found in the grains like wheat, rye, and barley. Patients have to follow strict dietary guidelines and avoid most bread, pasta, and cereal, in order to manage their symptoms. But gluten isn’t limited to food products: It can also be found in some cosmetics. While makeup containing gluten causes no issues for many people with celiac, it can provoke rashes in others or lead to more problems if ingested. For those folks, gluten-free makeup is an option.

4. The name comes from 1st-century Greece.

A 1st-century Greek physician named Aretaeus of Cappadocia may have been the first person to describe celiac disease symptoms in writing [PDF]. He named it koiliakos after the Greek word koelia for abdomen, and he referred to people with the condition as coeliacs. In his description he wrote, “If the stomach be irretentive of the food and if it pass through undigested and crude, and nothing ascends into the body, we call such persons coeliacs.”

5. There are nearly 300 celiac disease symptoms.

Celiac disease may start in the gut, but it can be felt throughout the whole body. In children, the condition usually manifests as bloating, diarrhea, and abdominal discomfort, but as patients get older they start to experience more “non-classical” symptoms like anemia, arthritis, and fatigue. There are at least 281 symptoms associated with celiac disease, many of which overlap with other conditions and make celiac hard to diagnose. Other common symptoms of the disease include tooth discoloration, anxiety and depression, loss of fertility, and liver disorders. Celiac patients also have a greater chance of developing an additional autoimmune disorder, with the risk increasing the later in life the initial condition is diagnosed.

6. Some patients show no symptoms at all.

It’s not uncommon for celiac disease to be wrecking a patient’s digestive tract while showing no apparent symptoms. This form of the condition, sometimes called asymptomatic or “silent celiac disease,” likely contributes to part of the large number of people with celiac who are undiagnosed. People who are at high risk for the disease (the children of celiac sufferers, for example), or who have related conditions like type 1 diabetes and Down syndrome (both conditions that put patients at a greater risk for developing new autoimmune diseases) are encouraged to get tested for it even if they aren’t showing any signs.

7. It’s not the same as wheat sensitivity.

Celiac is often confused with wheat sensitivity, a separate condition that shares many symptoms with celiac, including gastrointestinal issues, depression, and fatigue. It’s often called gluten sensitivity or gluten intolerance, but because doctors still aren’t sure if gluten is the cause, many refer to it as non-celiac wheat sensitivity. There’s no test for it, but patients are often treated with the same gluten-free diet that’s prescribed to celiac patients.

8. It's not a wheat allergy either.

Celiac disease is often associated with wheat because it's one of the more common products containing gluten. While it's true that people with celiac can't eat wheat, the condition isn't a wheat allergy. Rather than reacting to the wheat, patients react to a specific protein that's found in the grain as well as others.

9. It can develop at any age.

Just because you don’t have celiac now doesn’t mean you’re in the clear for life: The disease can develop at any age, even in people who have tested negative for it previously. There are, however, two stages of life when symptoms are most likely to appear: early childhood (8 to 12 months) and middle adulthood (ages 40 to 60). People already genetically predisposed to celiac become more susceptible to it when the composition of their intestinal bacteria changes as they get older, either as a result of infection, surgery, antibiotics, or stress.

10. Not all grains are off-limits.

A gluten-free diet isn’t necessarily a grain-free diet. While it’s true that the popular grains wheat, barley, and rye contain gluten, there are plenty of grains and seeds that don’t and are safe for people with celiac to eat. These include quinoa, millet, amaranth, buckwheat, sorghum, and rice. Oats are also naturally gluten-free, but they're often contaminated with gluten during processing, so consumers with celiac should be cautious when buying them.

11. Celiac disease can be detected with a blood test.

Screenings for celiac disease used to be an involved process, with doctors monitoring patients’ reactions to their gluten-free diet over time. Today all it takes is a simple test to determine whether someone has celiac. People with the condition will have anti-tissue transglutaminase antibodies in their bloodstream. If a blood test confirms the presence of these proteins in a patient, doctors will then take a biopsy of their intestine to confirm the root cause.

12. The gluten-free diet doesn’t work for all patients.

Avoiding gluten is the most effective way to manage celiac disease, but the treatment doesn’t work 100 percent of the time. In up to a fifth of patients, the damaged intestinal lining does not recover even a year after switching to a gluten-free diet. Most cases of non-responsive celiac disease can be explained by people not following the diet closely enough, or by having other conditions like irritable bowel syndrome, lactose intolerance, or small intestine bacterial overgrowth that impede recovery. Just a small fraction of celiac disease sufferers don’t respond to a strict gluten-free diet and have no related conditions. These patients are usually prescribed steroids and immunosuppressants as alternative treatments.

13. If you don’t have celiac, gluten probably won’t hurt you.

The gluten-free diet trend has exploded in popularity in recent years, and most people who follow it have no medical reason to do so. Going gluten-free has been purported to do everything from help you lose weight to treat autism—but according to doctors, there’s no science behind these claims. Avoiding gluten may help some people feel better and more energetic because it forces them to cut heavily processed junk foods out of their diet. In such cases it’s the sugar and carbs that are making people feel sluggish—not the gluten protein. If you don’t have celiac or a gluten sensitivity, most experts recommend saving yourself the trouble by eating healthier in general rather than abstaining from gluten.

14. The numbers are growing.

A 2009 study found that four times as many people have celiac today than in the 1950s, and the spike can’t be explained by increased awareness alone. Researchers tested blood collected at the Warren Air Force Base between 1948 and 1954 and compared them to fresh samples from candidates living in one Minnesota county. The results supported the theory that celiac has become more prevalent in the last half-century. While experts aren’t exactly sure why the condition is more common today, it may have something to do with changes in how wheat is handled or the spread of gluten into medications and processed foods.

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