Mosquitoes are a big part of the ecosystem, but often are a nuisance as they bite and feed off of us. Their bites cause itchy red bumps and spread infections and allergies in our bodies. But have you ever wondered why they bite certain people more than others? While some people are plagued by mosquito bites, others barely notice them. Here are some interesting facts about mosquitoes that you must know about!

1. Carbon Dioxide:

Mosquitoes are attracted to a certain smell that emits from the human body that is present in the human skin and sweat, mosquitoes can sense the carbon dioxide or CO2 we breathe out. The more active you are, the more CO2 you emit and the more mosquitoes will be attracted to you. Researchers are still investigating the cause of the variation of body odour that brings them to you, possibly genetics or certain bacteria. The unique combination of sweat and skin bacteria creates a scent that mosquitoes find irresistible. Some chemicals in sweat, like lactic acid and ammonia, are especially attractive to them.

2. Colours

While the reason isn't fully understood, mosquitoes seem to be drawn to dark colours like black more than lighter ones. So, ditch the dark outfit next time you're in mosquito territory. It has been noted that mosquitoes are more likely to leave lighter colours alone.

3. Heat and Vapour

Mosquitoes can detect your body's heat and water vapour, acting like a beacon guiding them right to you. So next time you're feeling sweaty, be aware you might be attracting a lot of mosquitoes. If you are working out or doing something that is making you sweat and your body heat rise, the mosquitoes nearby will be instantly attracted to you. Even mosquitoes are careful about who they pick as a host, some studies even suggest that they like a certain body temperature to feed off of.

An interesting fact about mosquitoes is that they can learn to like a host. They have their own preferences and if they meet a certain person who fits their criteria they might be the next host they move onto. In an older study, it showed that 20 per cent of people with mosquito-borne diseases accounted for 80 per cent of diseases transmitted in the population. They suggest that they only bite a certain set of people within the population.

4. Other factors:

Studies suggest mosquitoes might learn to prefer certain people based on things like what you've been drinking. In a 2002 study, there could be many reasons they like alcohol to making your body temperature high etc. Even pregnant women seem to be extra attractive to them due to higher body temperature and CO2 output.

In recent times, there has been a noticeable increase in heart-related risks among Indians in their 20s. In the past, heart disease was mainly a problem of old age, but the changing lifestyles, poor eating habits, and rising stress levels have changed this trend. This has increased the number of doctors recommending a calcium heart scan also called a coronary calcium scan, even for young adults.

What Is A Calcium Heart Scan?

A calcium heart scan is a quick painless imaging test that checks for calcium deposits in the coronary arteries. These deposits are one of the earliest signs of atherosclerosis, a condition in which plaque builds up inside the arteries and restricts the flow of blood.

The significance of this test is that it can uncover hidden risk even before symptoms such as chest pain and breathlessness appear.

Why Young Indians Are At Higher Risk

Young Indians face multiple risk factors today. Sedentary lifestyles long working hours also lack of physical activity, smoking and increased intake of processed foods are major contributors. Ailments like diabetes, obesity, high cholesterol and hypertension are also being seen at a much younger age.

Family history also matters a lot especially in the Indian population who are genetically more prone to early heart disease.

The worry is that many young people seem healthy on routine tests but may still have silent plaque build-up. This is where a calcium score is useful. The higher the score, the more likely you are to have future heart problems, and doctors can take early steps to prevent them such as lifestyle changes or medication.

Why Early Screening Matters

Another important point is that heart attacks in young Indians are often more sudden and severe. This makes early screening all the more important. Calcium heart scans don’t replace your routine check-up, but they do provide an extra level of insight in helping to identify hidden cardiovascular risk.

This scan is not about instilling fear but about early awareness and prevention. Heart disease if found early can often be controlled or prevented. This small step can help to protect young adults with risk factors for long term heart health.

(By Dr. Surendra Nath Khanna, Chairperson, Adult Cardiac Surgery & Heart - Lung Transplant at Artemis Hospital, Gurugram).

Climate change caused a 10 per cent global increase in Salmonella antibiotic resistance genes between 1940 and 2023, according to the first-of-its-kind study published in The Lancet Planetary Health journal today.

Antimicrobial resistance (AMR) is mainly driven by the overuse and misuse of antibiotics, which allows resistant bacteria to survive and spread.

However, rising temperatures and changing rainfall patterns can influence how bacteria survive, mutate, and spread, potentially increasing the exchange of antibiotic resistance genes.

“The accumulated evidence suggests that climate change is an accelerating force behind the global spread of antimicrobial resistance,” the study authors wrote in the paper.

What Are The Findings?

The study provides supporting evidence that AMR doesn’t just increase steadily as temperatures rise, but that the number of resistance genes changes over time in a more complicated way, depending on both temperature and rainfall. This suggests that environmental changes can speed up how bacteria adapt to antibiotics.

“These findings reinforce the idea that climate change alters microbial ecological stability and accelerates resistance evolution across human, animal, and environmental reservoirs," said the global researchers.

How Was The Study Conducted?

The current study analyzed the genomes of more than 480,000 Salmonella samples from 139 countries, collected between 1940 and 2023, and compared levels of antibiotic resistance genes with changes in average temperature and rainfall over time.

Of the total, 82 per cent of countries saw increases in antibiotic resistance genes in Salmonella, with the strongest climate-associated increases occurring in the Middle East and North Africa, followed by South Asia and Sub-Saharan Africa.

While the study shows a link between climate change and antibiotic resistance genes in Salmonella, it does not prove that climate change directly causes the increase.

The study also used a model to predict the change in antibiotic resistance genes in Salmonella by 2100 under different climate emissions scenarios.

The model suggests that if countries meet low-emission climate targets and strengthen efforts to use antibiotics responsibly, levels of resistance genes could be 24% lower than under the highest-emission scenario. However, they caution that these projections, as with all models, involve uncertainty.

The researchers stressed the need to consider climate change when monitoring and addressing AMR. They add that stronger climate action, alongside responsible antibiotic use and improved disease surveillance across humans, animals, and the environment, will be important in limiting the future spread of AMR.

What Is Salmonella?

As per the US Food and Drug Administration (FDA), Salmonella is a group of bacteria that can cause gastrointestinal illness and fever called salmonellosis. It can be spread by food handlers who do not wash their hands and/or the surfaces and tools they use between food preparation steps. It can also happen when people consume uncooked and raw food. Salmonella can also spread from animals to people.

Common symptoms of Salmonella include

• diarrhea,
• fever,
• stomach cramps 6 hours to 6 days after being exposed to the bacteria.

Children younger than 5, adults 65 and older, and people with weakened immune systems are more likely to have severe illness.

Indian summers are not just uncomfortable; they are becoming increasingly dangerous. With temperatures frequently crossing 45–48°C, heatwaves are putting excess stress on the human body, which hitherto had not experienced this level of heat strain. Now, add smoking to this already hostile environment and, like adding fuel to a fire, two harmful components combine to multiply the damage. Dr Shubham Garg, Director of Surgical Oncology, Dharamshila Narayana Superspeciality Hospital, Delhi, spoke about the risks of stepping out to grab a smoke during extreme heatwaves.

Smoking during heatwaves doesn’t just worsen existing risks; it accelerates dehydration, strains the heart, damages the lungs, and pushes the body closer to heat exhaustion or heatstroke. Here’s why lighting up in extreme heat is far more dangerous than most people realise.

Heatwaves Already Stress the Body—Smoking Adds Fuel to the Fire

When temperatures soar, your body works overtime to cool itself. A host of processes happen to aid in this—your blood vessels dilate, there could be an increase in heart rate, and sweating intensifies in order to regulate body temperature. When you smoke, it interferes with these very natural defense mechanisms of your body.

Nicotine results in vasoconstriction—narrowing of blood vessels—which makes it very difficult for the body to release heat trapped inside. The carbon monoxide from cigarettes reduces oxygen delivery to tissues. The result? Less oxygen reaches your organs, which are, in fact, working harder in the extreme heat. This is a perilous combination that can affect the body in many ways.

Dehydration Happens Faster Than You Think

A heatwave leads to sweating and, consequently, loss of fluids and electrolytes. And when you go for smoking a cigarette, it leads to fluid loss and delayed hydration. Nicotine acts as a mild diuretic, which contributes to increased fluid loss. Smoking also suppresses thirst signals, thus delaying hydration.

Collectively these factors raise the risk of severe dehydration, which can trigger dizziness, muscle cramps, low blood pressure, and confusion—all of which are early signs of heat exhaustion. Many smokers ignore these signs or dismiss them altogether.

A Deadly Mix for the Heart

Cardiovascular strain can happen independently through either smoking or heat. That in itself is a threat one should keep an eye out for. However, when combined, they pose a compelling risk of:

1. Sudden spikes or drops in blood pressure
2. Irregular heart rhythms
3. Heat-induced cardiac events

During extremely hot weather conditions, especially during a heatwave, the heart has to exert more effort to maintain circulation and cooling in the body. Smoking elevates heart rate and blood pressure further while also thickening the blood and increasing the risk of heart attacks and strokes, especially in people with pre-existing diabetes, hypertension, or heart disease.

Lungs Struggle More in Hot, Polluted Air

Hot weather is bad for air pollution levels too, as it traps smoke, dust, and harmful gases close to the ground. When one smokes in these conditions, it severely compromises lung function:

1. Airways become inflamed and constricted
2. Oxygen exchange efficiency drops
3. Symptoms like breathlessness, coughing, and chest tightness worsen

For people with asthma, COPD, or other respiratory conditions, smoking during a heatwave is likely to trigger severe flare-ups and emergency hospital visits.

Heat + Smoking Accelerates Ageing and Skin Damage

Extreme heat is damaging not just for the heart but for the skin as well. The skin becomes dehydrated, and collagen breaks down. Smoking compounds this damage by reducing blood flow and oxygen supply to the skin.

The result:

1. Faster wrinkles and sagging skin
2. Increased pigmentation and dullness
3. Delayed healing of rashes, infections, and sun damage

In short, smoking during summer doesn’t just harm internal organs; it visibly accelerates the ageing process.

Higher Risk of Heat Exhaustion and Heatstroke

Smoking reduces the body’s ability to regulate temperature effectively. This makes smokers more vulnerable to heat exhaustion (fatigue, nausea, headache, dizziness) and heatstroke (confusion, collapse, organ failure).

Heatstroke is a medical emergency and can be fatal if not treated promptly. Smokers often misread early warning signs as ‘normal summer weakness,' thus delaying care.

Why Cutting Down Isn’t Enough

Many smokers try to “reduce” smoking during summer. While any reduction helps, heatwaves are one of the worst times to smoke at all. Even a few cigarettes can significantly increase physiological stress when temperatures are extreme.

Smoking during heatwaves is not just bad—it’s dangerously synergistic. If there ever is a time to quit, or at least pause, this should be it. Because in peak summer, smoking doesn’t just harm you slowly. It fast-tracks damage, turning heat into a silent but serious health threat. In extreme heat, choosing not to smoke isn’t just a lifestyle choice—it’s a life-saving one.