As temperatures around the world rise because of climate change, the human body is increasingly confronting a little-understood and increasing hazard: excessive heat. From enduring heatwaves to sweltering heat waves with high humidity, what used to be a seasonal annoyance is now a worldwide health risk. But how hot is too hot for the human body? At what point does heat become deadly—and why?

In 2020, an article published in Science Advances identified a precise threshold by which the human body cannot survive: 95°F (35°C) wet-bulb temperature. Unlike regular temperature readings, wet-bulb temperature takes into consideration both heat and humidity. It is measured with a thermometer covered in a cloth soaked in water, replicating the way the human body dissipates heat—by evaporating sweat.

If the air surrounding the body is too moist, sweat does not evaporate. When this system breaks down, so does the body's control over internal temperature. The result? A speedy and potentially dangerous increase in core temperature.

In perspective, 115°F (46.1°C) air temperature with 30% humidity yields a wet-bulb temperature of approximately 87°F (30.5°C)—still survivable. However, a seemingly "cooler" 102°F (38.9°C) day with 77% humidity brings the wet-bulb temperature to the lethal 95°F (35°C) mark.

Once wet-bulb temperatures reach this tipping point, sweat can no longer evaporate fast enough to cool the body. Even if the skin is wet, the internal temperature continues to climb. At this stage, hyperthermia sets in—defined by a body temperature above 104°F (40°C)—leading to symptoms like confusion, rapid heart rate, organ failure, and even death.

Who’s Most at Risk?

Although no human can live above a wet-bulb temperature of 95°F, not all people are equally at risk in lower heat exposures.

• Older people, because of impaired thermoregulation.
• Obese or chronically ill people, such as those with cardiovascular disease.
• Those on certain medications, e.g., antipsychotics or beta-blockers.
• Workers outdoors and athletes, whose exertion increases body heat.

Even healthy individuals can succumb to lower wet-bulb temperatures if they are exerting themselves in direct sun or in poorly ventilated environments.

What Happens Inside the Body During Heat Exposure?

The human body contains approximately 60% water, and fluid balance is inextricably linked with temperature regulation. In hot temperatures, the body loses water quickly through sweat and respiration. If it is not replaced, dehydration occurs, causing blood volume to decrease. This affects anything from organ function to delivery of oxygen at the cellular level.

Meanwhile, the thermoregulatory system, which depends on blood flow to shuttle heat from internal organs out to the skin, starts to fail. If this cooling circuit fails, internal organs become overheated, cells start dying, and a chain of failure results in heat stroke or cardiovascular collapse.

How Hot Is Too Hot, Really?

Whereas wet-bulb temperature gives us one measurement, research indicates the ambient air temperature limit of human survival is probably between 104°F and 122°F (40°C–50°C). 122°F is at the limits of what the body can withstand while keeping its core temperature stable, says a 2021 Physiology Report.

A different approach to research implies that the temperature at which the body begins to sweat is 89.6°F (32°C)—the beginning of heat strain. Thus, danger doesn't begin at extreme temperatures only; it accumulates with time, particularly due to long exposure and high humidity.

The U.S. Environmental Protection Agency (EPA) has documented that heat directly caused 11,000 fatalities in the United States between 1979 and 2018, although the actual number is probably much greater because underreporting is likely to have occurred. While hurricanes or flooding may be dramatic, they kill openly, but heat waves are deadly killers that silently take victims in poor communities, older people, and those not having air conditioning.

Moreover, heat exacerbates existing conditions, increasing the possibility of strokes, heart attacks, and breathing difficulties during heat waves.

How to Survive Extreme Heat?

We may not be able to manipulate the weather, but we can manage our environment and lifestyle. Experts advise:

• Rehydrate with electrolytes, not plain water. Sweating excessively loses salt and minerals necessary for cellular processes.
• Lower internal body temperature by bathing or showering with cool water.
• Avoid sun exposure, particularly between 10 AM and 4 PM.
• Dress in light, loose clothing and have lighter, more frequent meals.

Use extra caution with electric fans during high heat; they can accelerate evaporation and boost dehydration.

In addition, the Centers for Disease Control and Prevention (CDC) recommends visiting during heatwaves susceptible populations—i.e., people who are frail or have disability and ensuring air conditioning, shades, or available cooling resources like fans or air conditioning are at their disposal.

The highest temperature that a human can tolerate is not one number—it's a function of heat, humidity, and time. Wet-bulb temperatures over 95°F are universally lethal within a few hours, but even lower temperatures can be severely dangerous under the right conditions. As climate change accelerates, our knowledge of and readiness for extreme heat must keep pace. This isn't merely a meteorological issue—it's a public health emergency in the making.

As the global obesity and diabetes epidemic continues to surge, the demand for effective, safe, and sustainable weight management solutions has never been higher. In the United States alone, millions struggle with type 2 diabetes and obesity, conditions that not only shorten lives but also diminish quality of life. While medications like Ozempic (semaglutide) and other GLP-1 agonists have changed the landscape of diabetes and weight loss therapy, they come with a significant drawback: the loss of precious muscle mass. Now, a groundbreaking drug in development could offer a better way—a true “exercise in a pill” that burns fat, lowers blood sugar, and preserves muscle.

GLP-1 agonists, including Ozempic and Wegovy, have become household names for their dramatic effects on weight loss and blood sugar control. These drugs work by mimicking a gut hormone that signals the brain to reduce appetite and slow gastric emptying, helping people eat less and lose weight. However, studies have shown that up to 60% of the weight lost on these medications can come from lean muscle, not just fat.

In a groundbreaking development that could reshape the weight loss and metabolic disease treatment, researchers from Sweden have introduced an experimental oral drug that mimics the benefits of exercise — without the need for injections, and more importantly, without compromising muscle mass.

Led by a collaboration between the Karolinska Institutet, Stockholm University, and biotech company Atrogi AB, the newly developed β2-adrenergic receptor (β2AR) agonist has shown promising results in burning fat, lowering blood sugar, and preserving lean muscle — a trio of effects that current popular drugs like Ozempic (semaglutide) struggle to achieve simultaneously.

“This drug represents a completely new type of treatment and has the potential to be of great importance for patients with type 2 diabetes and obesity,” said study lead author Professor Shane Wright from Karolinska Institutet.

Why Muscle Loss Matters in the Weight Loss Drug Debate?

Drugs like Ozempic and Wegovy, classified as GLP-1 receptor agonists, have become increasingly popular for treating obesity and type 2 diabetes. Their efficacy in reducing hunger and slowing gastric emptying has made them a household name. However, several studies have indicated that up to 60% of the weight lost using GLP-1 drugs may be lean muscle mass, not fat. That’s a dangerous trade-off.

Muscle mass isn’t just about strength or athletic performance — it is metabolically active tissue, meaning it burns more calories at rest than fat and plays a crucial role in regulating blood sugar levels. Losing muscle slows metabolism, increases insulin resistance, and can even raise the risk of osteoporosis, particularly in older adults.

The need for a safer alternative has never been greater — and this new pill could be the answer.

This muscle loss isn’t just a cosmetic issue. Muscle tissue is metabolically active, burning more calories at rest than fat. Losing muscle lowers the resting metabolic rate, making it harder to keep weight off long-term. Muscle is also essential for strength, mobility, and healthy aging, and it plays a crucial role in regulating blood sugar. For older adults, muscle loss can accelerate frailty, increase the risk of osteoporosis, and reduce life expectancy.

How This Drug Works?

Unlike GLP-1 agonists, which work through the brain-gut axis by reducing hunger, the new drug directly targets skeletal muscle metabolism. It’s designed to activate β2-adrenergic receptors, simulating the body’s physiological response to physical exercise. This boosts the metabolism of muscle tissue and promotes fat burning without suppressing appetite or causing lean tissue degradation.

In animal studies, the compound was shown to improve body composition, reduce fat mass, and preserve or even enhance muscle tissue. These results were so promising that researchers quickly moved into a Phase I human clinical trial

“Our substance appears to promote healthy aging and weight loss—and, in addition, patients do not have to take injections,” said Professor Shane Wright of the Karolinska Institutet, one of the study’s lead authors.

Early Human Trials

The Phase I trial included 48 healthy volunteers and 25 people with type 2 diabetes, all of whom were administered a 2.5 mg daily dose of the tablet for 28 days. Participants’ key health metrics — including heart rate, blood pressure, and glucose levels — were closely monitored.

The results were encouraging. Both healthy participants and those with diabetes tolerated the drug well. The only notable side effect was a mild, transient increase in heart rate early in the trial, which resolved by day 28. Importantly, there were no significant differences in heart rate or blood pressure between the groups by the end of the study.

One participant experienced a severe adverse event, but this occurred in someone with preexisting cardiac abnormalities and resolved without complications. The connection to the study drug remains uncertain, and overall, the safety profile appears favorable.

At the end of the trial, all participants had plasma drug levels consistent with therapeutic dosing, confirming compliance and supporting the validity of the safety data.

Why is the Drug Different From Ozempic and Other GLP-1 Agonists?

The most significant advantage of this new β2-agonist is its ability to preserve muscle mass during weight loss. While GLP-1 drugs work primarily by reducing caloric intake, often at the expense of muscle, the new drug targets muscle metabolism directly. This distinction could be transformative, especially for older adults, people with chronic illnesses, and anyone concerned about muscle health.

“Muscles are important in both type 2 diabetes and obesity—and muscle mass is also directly correlated with life expectancy,” said Professor Tore Bengtsson, a molecular biologist at Stockholm University and co-author of the study. “Our results point to a future where we can improve metabolic health without losing muscle mass.”

With phase 1 safety data in hand, the research team is moving forward with larger, longer phase 2 trials. These studies will focus on the drug’s effects on muscle mass, glucose control, insulin sensitivity, and overall metabolic health in people with type 2 diabetes and obesity. If successful, this new therapy could become a first-in-class oral medication that offers the benefits of exercise—without the need for injections or the risk of muscle loss.

Is This A Non-Injection Weight Loss Future?

Aside from its unique muscle-preserving benefits, another major selling point is its oral delivery. Unlike Ozempic or Mounjaro, which require regular injections, this pill is taken once daily, making it easier to incorporate into everyday life — a feature that could improve adherence, accessibility, and affordability.

This shift could democratize weight loss and diabetes management therapies, especially for patients who are needle-averse or face barriers to injectable drug regimens.

The development of an “exercise in a pill” is more than just a scientific curiosity—it represents a paradigm shift in how we approach chronic metabolic diseases. For millions who struggle to exercise due to physical limitations, age, or illness, such a drug could provide life-changing benefits. Even for those who can be active, combining this therapy with lifestyle changes could amplify results.

However, experts caution that no pill can fully replace the wide-ranging benefits of physical activity, which include cardiovascular health, mental well-being, and bone strength. Still, the potential to safely burn fat and preserve muscle—especially for vulnerable populations—marks a significant leap forward.

Sometimes we all have to look for reasons to exercise. "Being healthy" may not be enough for many people, however getting rid of a constant source of discomfort may be just what you need to start exercising, more specifically walking.

A study published on June 13 in JAMA Network Open found that people who walked for about 100 to 125 minutes each day had a 23% lower chance of getting chronic low back pain compared to those who walked less than 78 minutes daily. Walking at a medium or quick pace also seemed to lower the risk of back pain, but not as much as the total time spent walking.

Chronic low back pain—pain that lasts for at least three months straight—is very common. It affects many adults and is expected to become even more widespread globally in the coming years. This is a significant finding because walking is an easy, cheap, and accessible activity that many people can do to help reduce the burden of back pain.

How Walking Time and Speed Directly Affects Back Pain?

The study looked at over 11,000 adults, around 55 years old on average, who lived in Norway. When the study began, none of them had chronic low back pain.

Participants wore devices that tracked their movement and how fast they walked for a week. This gave researchers much better information about their walking habits than simply asking them to remember.

The walking data was collected between 2017 and 2019. Then, from 2021 to 2023, researchers asked the participants if they had experienced any chronic pain or stiffness in their lower back. Basically, the study examined the link between walking and staying free of chronic low back pain.

It was found that walking less than 78 minutes per day was linked to the highest risk of chronic low back pain. From there, the findings showed:

• Walking between 78 and 100 minutes daily was linked to a 13% lower risk of chronic low back pain.
• Walking between 101 and 124 minutes daily was linked to a 23% lower risk of chronic low back pain.
• Walking over 125 minutes daily was linked to a 24% lower risk of chronic low back pain.

The research also showed that walking at a medium or quick speed (at least 2.8 miles per hour) reduced the risk of chronic low back pain by up to 18%.

Other studies have also supported the idea that walking can reduce pain, including one last year that suggested walking can increase the time between episodes of low back pain.

However, this new report has some limitations. Importantly, the study was done with adults in Norway. People in some parts of the world, like Europe, tend to walk more than people in other regions, such as the U.S. This means the results might not always apply to everyone around the world, especially since some populations are generally more active and healthier.

How Walking Helps Keep Back Pain at Bay?

Increases Movement and Reduces Stiffness

Walking helps you move more freely and makes your back less stiff. It strengthens core muscles, loosens connective tissues, and improves joint movement, leading to greater flexibility and less pain.

Boosts Blood Flow

Walking enhances blood circulation throughout your body. This delivers fresh, oxygen-rich blood to your back, which is crucial for reducing inflammation and promoting healing in the area.

Eases Strain

The combined benefits of walking, including improved movement and weight management, significantly reduce the stress and strain placed on your lower back, offering noticeable relief.

Improves Mood

Walking also offers a mental boost. Exercise releases "feel-good" chemicals, improving your mood and overall well-being. This can help ease the psychological stress often associated with persistent low back pain.

‘Inner Child’ is Health and Me's new mental health series where we deep dive into lesser-known aspects of child psychology and how it shapes you as you grow up. Often unheard, mistaken, and misunderstood, in this series we talk about the children’s perspective and their mental health, something different than you might have read in your parenting books. After all, parenting is not just about teaching but also unlearning.

Sometime 90 years ago, a psychologist proposed that birth order could have an impact on what kind of person the child becomes once they grow up. It is true, childhood, of course, shapes your personality as you grow up. But what does it mean to be the last one in the birth order?

It was the COVID-19 pandemic, when I started to jot down how I felt when suddenly I was home with my entire family under the same roof. Thanks to lockdown restrictions, I was again reminded that I am the youngest in the family. This is when I started writing a journal that I thought I would publish into a book once I finished it. I called it "To Be The Second Born". I jotted down my experience of being the youngest in the house, especially when everyone around me, including both my parents, are the oldest in their family.

Contrary to the belief that we are spoiled, I felt that we are often unheard and ignored, because we are always "too young" to be taken seriously. As a result, we revolt and are tagged as defiant. Five years down the line, my boss shared an Instagram reel that described how I felt. The reel went on to talk about how no one sees the struggle of a younger sibling. Or how everyone thinks they always got it easy. When, in reality, it is often because we are so used to being misunderstood that we shut ourselves down, not telling anyone about what is going on. Instead of fighting the 'defiant' tag, we start to live with it. We take responsibility, but never talk about it, because we know we will not be heard.

Watching that reel made me realize that it is not just me, but a lot of younger siblings who feel the same. While the book seems like a distant dream, a piece on it doesn't.

If you, too, feel the same, this one is for you.

ALSO READ: Inner Child: When the Bullied Turns Into A Bully – Psychology Of A Victim’s Defense Turned Attack

Too Young To Matter?

Krishna, 32, who is originally from Bihar, now in Pune, is the youngest of all the siblings. She has three older siblings, and she tells me that she often felt like a "stupid".

This is because her older siblings were very "authoritative". When asked why, she says, "I think culturally, we tend to equate age with wisdom and hence, anyone older than us automatically gets elevated to wiser in comparison."

She tells me that she, too, struggled putting her foot down and was often treated as a pushover. It was not until she turned 25 that she openly started to question whatever she was told. Before that, she used to hide things just to avoid confrontation.

The reaction was not pleasant. "There was a lot of gaslighting," she tells. However, she stayed firm and made it clear that she needs to be heard too, and should not be controlled.

To get a better understanding of why this happens, I spoke to Dr Rahul Chandok, who is a senior consultant and head of psychiatry at Artemis Lite, NFC, Delhi. Chandok explains, "When older siblings are in charge of younger ones and always telling them what to do or correcting them, the younger child may start to doubt themselves or feel bad about themselves. Being told what to do all the time can make it harder for them to think for themselves or trust their own decisions. As time goes on, they may start to hide their thoughts or not take the lead because they are afraid of being judged or criticized."

This dynamic can also make younger siblings more anxious or angry. Kati Morton, who is a licensed therapist and a public speaker renowned for her YouTube channel focused on mental health, points out that the youngest children might develop a heightened need for external validation to feel secure about their decisions and actions, potentially leading to anxiety about making mistakes or disappointing others.

Chandok explains that this is also true because of repeated invalidation. The reason why younger siblings may often feel like a pushover is because they have been constantly told that their opinions are wrong, "just because they are younger".

"Over time, such behaviors can hurt self-esteem, lower self-confidence, and make it hard to speak up for themselves in relationships or at work," explains Chandok.

But, Younger Siblings Are Perceived As Defiant And Indifferent

This is because people often get the wrong idea, explains Chandok. "If a child is always told what to do and never asked what they think, pushing back may be the only way they feel in control. If they don't follow directions, break rules, or act like they don't care, they might be trying to say, 'I want to be heard'," he explains.

However, not always are the relationships between a younger and older sibling as stringent. For instance, Ayush Upadhayay, 26, who has a three-year age gap with his older sibling, shares that while he has felt unheard, it has not always been a constant feeling. He tries to explain this and says, "They have responsibilities and feel that we are not yet ready for it."

When asked if that made him feel neglected or incapable, he said that earlier it used to make him feel that, however, now, he has confronted his older sibling. "Initially, she defended her behavior, later, she understood why I felt that way."

In Such Scenarios, What Can Families Do?

Families need to make room for everyone to have a say, no matter how old they are. Chandok also explains that families must encourage kids to talk to each other openly. This conversation must allow younger kids to be heard without being interrupted or judged. "Older siblings can make a big difference by asking for their opinions, respecting their choices, and not being bossy," says Chandok.

From a young age, parents too should encourage younger kids to make decisions, make choices, and not just praise them for following rules, but also being unique, thinking differently, even when their opinions may not match with the rest.