How to avoid heatstroke amid soaring temperatures | An expert take

As heatwave conditions intensify across India with temperatures reaching 40–45°C across many states, hospitals are beginning to see a worrying trend. Patients are arriving confused, dehydrated, and often unconscious after prolonged exposure to extreme heat. Many ignore early heatstroke symptoms like fatigue, dizziness, and nausea, only seeking help when the condition turns critical.

This is not just about seasonal discomfort. It is emerging as a serious public health concern linked to rising temperatures, climate change, and lack of awareness around prevention and early treatment.

To unpack what heatstroke really is, how it differs from dehydration, and how people can protect themselves, Firstpost spoke with Dr Professor Amlendu Yadav, Head of the Department, Emergency Medicine at Atal Bihari Vajpayee Institute of Medical Sciences and Dr Ram Manohar Lohia Hospital, New Delhi.

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In a detailed interaction, Dr Yadav explains the science behind heatstroke, why cases are rising, how specialised treatment works and what simple steps can save lives during extreme heat.

What is heatstroke and why it is different from dehydration

Heatstroke is a severe medical condition in which the body loses its ability to regulate temperature.

“Heat stroke, if we have to define this, is a condition where body's temperature exceeds 105 degrees Fahrenheit, along with Central Nervous System symptoms, which include confusion, nausea, vomiting, agitation, drowsiness, unconsciousness, and to an extent coma and seizures.”

He explains that the key issue is the body’s inability to cool itself. “Body's mechanism fails to control the body's temperature. In simple terms, the body is not able to control its temperature, it is only possible by external cooling.”

This is what makes it different from fever. “In fever, body has the ability to increase or decrease the temperature, but in heat stroke, once body goes beyond certain temperature, that certain temperature is 105 degrees Fahrenheit. If temperature goes beyond that, body's ability to bring the temperature down is not there.”

He also draws a clear distinction with dehydration. “Dehydration is something in which the body's blood volume is decreased. I mean, the circulating blood volumes decreases, the body's water percentage decreases. In hyperthermia, it is all about temperature and dehydration is about blood volume or liquid."

Early warning signs people tend to ignore

Doctors say the early symptoms are often missed or ignored until it is too late.

“When the person is working in a high ambient temperature of 40-45 degrees with high humidity, the body's ability to bring down the temperature also goes away.”

He explains how symptoms build up. “Usually the temperature keeps on increasing  and the patient gets dehydrated, confused and starts feeling thirsty, nauseous, and pukish.”

By the time patients reach the hospital, many are already in a critical condition. “Most of the patients of heat strokes that come to us at the hospital, are confused, and unconscious and they don't know what has actually happened to them and they are not able to remember what was happening just before this event.”

Why heatstroke cases are rising in India

The increase in cases is linked to broader environmental changes.

“It is all because of climate change. We are seeing such diseases. Earlier during my training, I was not even aware of the term heat stroke.”

"It is only during the last few years we have come across this term and we have seen patients of heat stroke," noted Dr Yadav.

He highlights recent data. “I have seen our heat stroke unit started in May 2024 and that year 75 patients came to us out of which (because a few of them were coming late) 27 patients died.”

He also underlines the importance of timely care. “If we talk about the global mortality rate, the mortality of heat stroke is 80 percent if no treatment is given at the right time. But if the treatment is given at the right time, this mortality can be brought down to just 10 percent, provided the right kind of treatment at the right time is available.”

The most vulnerable include outdoor workers, children and elderly individuals. “Most of the patients which are coming or vulnerable population for the heat stroke are basically those people who are working outside in open areas like traffic police workers, construction workers, roadside vendors, prostitutes, beggars, and security guards.”

Inside the heatstroke unit and how it works

To deal with rising cases, a dedicated heatstroke unit was set up at Dr Ram Manohar Lohia Hospital in 2024. The focus is rapid cooling and constant monitoring.

“The most effective treatment is early cooling. We use cold water immersion where patients are submerged in chilled water under continuous monitoring,” Dr Yadav says.

The process involves lowering the patient’s body temperature gradually. “We bring down one degree in five to seven minutes. The aim is to reduce it to around 38 degrees Celsius within half an hour.”

The unit is equipped with specialised tubs, ice making machines, and monitoring systems. Ambulances are also being prepared to begin cooling even before patients reach the hospital. “Every minute counts. The earlier we start cooling, the better the chances of survival,” he adds.

One essential technique is  TACO which is TARPOLINE ASSISTED COOLING IN FIELD.

"We use a tarpaulin, where the patient is placed and then rock and rolled along with 10 to 15 kg of ice."

First aid steps to take during a heatstroke emergency

Immediate response can be life saving.

“If the patient is conscious, cold water can be given to them. They can also do cold sponging.”

He adds simple steps for bystanders. “Putting the patient in a shaded area, doing cold sponging, giving ORS and putting the ice in the axilla region. All those are the things for layman bystanders.”

He also mentions field techniques like tarpaulin assisted cooling using ice (TACO technique), though for most people, simple cooling methods are key. “The goal is to bring the temperature down as quickly as possible before reaching hospital.”

Daily precautions to prevent heatstroke

Prevention begins with awareness and simple habits.

“The first and the foremost thing which is required is awareness about the heat stroke.”

He lists key precautions.

Does carrying onion help in heatwave

Traditional remedies often resurface during extreme heat, including the idea of carrying onion for protection. Union Minister Jyotiraditya Scindia recently mentioned keeping an onion in the pocket to stay safe during a heatwave.

Upon asking whether such remedies work, Dr Yadav said, “I have never gone for this thing and I am not the right person to comment on that.”

He adds, “I have not seen or I have not came across any scientific material which suggests that onion will be helpful.”

Can heatstroke affect mental health

Heatstroke can have lasting neurological effects and can effect one's mental health severely in few unfortunate cases.

"Some of the patients," he recalls from his previous cases, "were not able to come back a similar mental status which they had just before the heat stroke."

He explains why. "If body's temperature remains elevated for more than 40 degree centigrade or more than 105 degree Fahrenheit, our body's protein get denatured."

"Our body runs on enzymes and enzymes are proteins. So to regenerate them, it takes time."

Recovery may not always be complete. “I really don't think they can be brought to the previous level.” At the same time, he alerts that not all patients will have these symptoms.

What to eat and avoid during extreme heat

Diet plays a critical role in prevention.

“We should take simple foods, which are during this, if I have to talk about in relation to a heat stroke or summer, we should take a lot of liquids.”

Dr Yadav recommends. “We can have juices, buttermilk, sweet lassi, lemon juice and coconut water.”

At the same time, certain foods should be avoided. “Heavy energy dense food should be avoided during the summertime, because that itself produces a lot of heat inside our body.”

On ice creams, he notes limited benefit. “Ice cream can just help for a short time to bring down the temperature.”

As heatwaves become more frequent and intense, doctors stress that awareness, early recognition, and timely action remain the most effective tools to prevent heatstroke related deaths.