Heat-related Illnesses: A Rising Public Health Concern In India

Thirteen people died and over 600 people suffered from heat stroke after attending a state award ceremony in Navi Mumbai, India in the month of April in 2023. More than 1 million people reportedly showed up to the event. The high temperatures, lack of available drinking water, and an unforeseen disaster led to the fatalities. 

This fatal incident is a sad reminder of India and the broader region’s vulnerability to climate change. After the country’s hottest February on record, April brought a severe heat wave last year. Last year, Indian officials issued heat warnings for several states, with temperatures reaching 109 degrees Fahrenheit in some parts of the country. Despite this, the existing Heat Action Plans in the country are inadequate in terms of funding, transparency, and legal foundations. 

The public health implications of soaring temperatures are bluntly seen in the case of the event that happened at Navi Mumbai. According to the National Family Health Survey 2019-21(NFHS 5) report, only 1 in 4 people in India have air conditioning or cooler facilities in their households. Out of which nearly 25% of households belong to urban settlements and only 15% belong to rural areas. The rest of the population lacks access to air conditioning and other cooling devices. This increases their risk of developing heat-related illnesses, especially for young children and older people. The lack of awareness about prevention and first aid for heat-related illnesses, as highlighted by the Navi Mumbai incident, also is a major concern. 

What are heat-related illnesses and why do they occur?

Heat-related illnesses are a spectrum of illnesses that can manifest as something as mild as a Heat Rash, Heat Cramps, Heat Exhaustion, Heat Oedema, to more dramatic complications like Heat Syncope, and Heat Stroke.

A heat-related illness can occur either due to exposure to hot weather or excessive physical exertion without fluid and electrolyte replacement. When the body is exposed to extreme heat, the body’s normal mechanism to lose heat to maintain optimal temperature fails. There is an imbalance between heat loss from the body and heat gained due to high ambient temperatures. Consequently, the body temperature continues to rise, leading to a direct toxic effect of heat on the body which further impacts the body’s heat regulation mechanism. This creates a vicious cycle and causes failure of multiple organs in the body. If not addressed urgently, it leads to death. 

What are the symptoms of these illnesses?

Heat rash is a skin irritation that can manifest as red clusters of pimples or small blisters across the body. It is caused when the ducts of the sweat glands get blocked after getting damaged by high temperatures and humidity.

Heat cramps are painful cramps in the muscles caused due to dehydration due to excessive sweating during strenuous activity or high temperatures. The sweating depletes water and salt in the body which leads to cramps. If fluids and salt are not replaced then this can progress to heat exhaustion. Such people tend to develop a low-grade fever along with tiredness.

Some people can also develop swelling of their legs as the vessels in the foot become leaky in high temperatures. This is known as heat edema. Pooling of fluids in the legs can also result in a sudden drop in blood pressure and fainting when a person stands for too long or stands up from sitting or lying down. This is known as heat syncope. 

Heat stroke is the most serious heat-related illness. It occurs when the body can no longer control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. When heat stroke occurs, the body temperature can rise to 106°F or higher within 10 to 15 minutes. Heat stroke can cause permanent disability or death if the person does not receive emergency treatment. Patients with heat stroke can also develop seizures, irrelevant talk, or become unconscious. 

It is essential to look for dark yellow/brown coloured urine, especially in the elderly, as it is a sign of dehydration which predisposes to all the above-mentioned conditions.

Who is at a higher risk of developing heat-related illnesses?

People working in hot and humid environments like brick-kiln workers, construction site workers, and athletes are at a higher risk of developing a heat illness. The risk is even higher if the person does not adequately replace the water and salt lost from the body as sweat. Older people, children, people recovering from a viral illness, people with other long-term diseases like diabetes, heart disease, and hypertension, and people with inadequate sleep are also a higher risk as their body’s coping mechanisms to tackle heat are weak.

First aid treatment for heat-related illnesses

One of the first steps is to keep the person hydrated by giving them cool fluids like water, oral rehydration solution (ORS), or fruit juices. Secondly, it is important to lower the person’s body temperature. This could be done by either using fans or air conditioners or by taking the person to the shade or any well-ventilated place and wetting their clothes. The clothes should be loosened in order to allow the body to lose its heat. 

In case of rashes keep the skin “cool and dry” by recurrent baths and application of lacto-calamine lotion that helps in reducing skin irritation. In case of muscle cramps or heat exhaustion, the person should avoid any physical exertion and should adequately hydrate themselves in order to replenish the lost fluids and electrolytes. If the person is having altered sensorium (talking irrelevantly), is comatose (not responding), has seizures, or feels irritable, kindly take them to the hospital as soon as possible. 

People with a history of other chronic conditions like heart disease, hypertension, cancer, or diabetes should be rushed to the hospital if a kind of heat-related symptom is noticed. Similarly, people belonging to extremities of age such as children and the elderly should receive urgent care if any heat illness symptom develops owing to their low coping ability with high temperatures.

Precautions to be taken to avoid heat-related illnesses

It is important to stay well hydrated and eat at frequent intervals to maintain an electrolyte and fluid balance in the body. The colour of the urine is a good indicator that can help in assessing the hydration status of the body. The darker it is, the higher the level of dehydration, and vice versa. 

It is also important to maintain a cool environment. For those indoors, fans, air conditioners, and proper ventilation will help in tackling the heat. However, for those working outdoors, it is important to provide them with a cool resting place and allow them to take frequent breaks from the heat. If possible, direct exposure to the sun should be avoided by providing outdoor workers with a tent or at least caps or hats. 

Relationship between diet and heat illnesses

Consuming food rich in non-esterified fatty acids like almonds, flaxseeds, and fish that contain omega-3 fatty acids and using plant oils like flaxseed oil, soybean oil, and canola oil can be helpful. As alcohol, tea, coffee, and carbonated soft drinks dehydrate the body, they should be avoided. Instead, ORS, and homemade drinks like lassi, torani (rice water), lemon water, buttermilk, etc. should be consumed. Fruits and vegetables high in water content such as watermelon, and grapes among others should be consumed as they can help replenish lost nutrients and fluids.

To summarize, staying hydrated and avoiding high outdoor temperatures and strenuous exercise during summer is key to avoiding heat-related illnesses. It is important to understand that climate change forms the core of this problem and a permanent solution to this problem would be to address factors causing environmental destruction and climate change.

Edited by Parth Sharma.

Image by Janvi Bokoliya.