Health concerns surge as heat waves loom: Take a look at the potential risks that rising temperatures pose

On 1 April, the IMD said that during the 2024 hot weather season (April to June or AMJ), above-normal maximum temperatures were likely over most parts of the country, except some parts of east and northeast India and pockets of northwest India, where normal to below-normal maximum temperatures were likely.

Warning about heat waves in the southern part of the country, the IMD said: “During April 2024, above-normal heatwave days are likely over many parts of south peninsula and adjoining northwest central India and some parts of east India and plains of northwest India.”

Also Read: IMD issues 3rd heatwave warning for several Telangana districts from 1 April

What is a heat wave?

A heat wave is a weather condition where the air temperature reaches levels that can be dangerous to the human body when exposed.

The IMD defines heat waves qualitatively and quantitatively. Qualitatively, it is based on temperature thresholds over a region — either in terms of actual temperature or its departure from normal.

In some countries, it may also be defined based on the heat index, which considers temperature and humidity, or extreme percentiles of temperatures.

The criteria for declaring a heat wave varies based on the region. They may be defined in at least two ways.

Departure-from-normal heat wave:

• Heat wave: When the departure from normal is between 4.5° C and 6.4° C.
• Severe heat wave: When the departure from normal is greater than 6.4° C.

Actual-maximum-temperature heat wave:

• Heat wave: When the actual maximum temperature reaches or exceeds 45° C.
• Severe heat wave: When the actual maximum temperature reaches or exceeds 47° C.

For declaration, the above criteria should be met in at least two stations within a meteorological sub-division for a minimum of two consecutive days, with the declaration being made on the second day.

For coastal stations, the criteria for describing a heat wave is the maximum temperature departure from normal is 4.5° C or more, and the actual maximum temperature is 37° C or higher.

The impact of heat waves on health is significant and can lead to various adverse outcomes.

The Indian government doesn’t recognise heat waves as a potential threat to human life, but healthcare professional and even the World Health Organisation consider heat waves to be life-threatening.

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Health impact of a heat wave

According to doctors, two common adverse effects of heat waves on human health are heat exhaustion and heat strokes.

“Heat exhaustion is a heat-related illness that can occur due to exposure to high temperatures, often accompanied by dehydration,” said Hyderabad-based Pranam Hospitals’ physician Dr Krisna Prasad.

“There are two types of heat exhaustion: Water depletion and salt depletion. Symptoms include confusion, dark-coloured urine, dizziness, fainting, fatigue, headache, muscle cramps, nausea, vomiting, pale skin, profuse sweating, and rapid heartbeat,” he explained.

Prasad added that treatment involves getting out of the heat, resting in a cool place, drinking fluids, removing tight clothing, taking a cool shower, and using cooling measures like fans or ice towels.

However, heat strokes can be worse. “A heat stroke — also known as a sun stroke — is an illness resulting in a body temperature greater than 40° C (104° F) — with symptoms like faintness and dry, warm skin, due to the inability of the body to control high temperatures,” said Prasad.

He added that other symptoms include swelling in the lower limbs, heat rashes on the neck, cramps, headache, irritability, lethargy, and weakness.

Heat strokes can lead to serious complications affecting the brain, heart, kidneys, and muscles. If left untreated, they can causing organ failure or potentially death.

“Heat strokes requires emergency treatment as they can quickly damage the brain, heart, kidneys, and muscles, with untreated cases at a risk of serious complications or death. Immediate cooling measures and medical attention are essential to prevent further harm and ensure recovery,” said Prasad.

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Increased mental distress

“People may feel distressed during the summer, but it shouldn’t lead to any disorder unrelated to the heat,” explained Hyderabad-based psychologist Dr Pragya Rashmi.

Talking to South First, she highlighted a unique issue during the summer: An increase in substance abuse, particularly the use of coolants.

Some individuals turn to cold beer or local alcoholic beverages, such as “hooch”, to cool themselves. They tend to fall asleep, which can be problematic.

Rashmi explained that dehydration can lead to a decrease in Vitamin B12 levels in the body since it is water-soluble. This can result in restlessness, difficulty focusing, and a lack of motivation.

To overcome these challenges, she advised maintaining optimal activity levels. “It’s important not to overexert oneself or be too lethargic. Hydration is crucial, not just through drinking water but also by applying lotion to keep the skin hydrated,” she said.

Rashmit recommended using a mild summer lotion to prevent skin irritation and dry lips. For individuals who have to spend time in the sun, she advised planning the day to minimise exposure during peak temperature and consuming fresh seasonal fruits.

Rashmi emphasised adjusting one’s food intake according to the season. It’s best to avoid excessive fried food or heavy dishes like biryani, which can be difficult to digest in hot weather. Instead, opting for lighter and more nutritious meals is recommended.

Also Read: Karnataka to witness above-normal temperature in summer

Symptoms to look out for

As temperatures continue to rise in various states, health officials and the IMD have issued warnings regarding potential health issues.

For example, the Telangana Health Department has advised people be alert to the following conditions that may arise due to high temperatures:

Altered mental sensorium with disorientation: This includes symptoms such as confusion, agitation, irritability, ataxia (lack of muscle coordination), seizures, and even coma.

Hot, red, and dry skin: The skin may feel excessively hot to the touch, appear flushed or red, and lack moisture or sweat.

Body temperature greater than 40° C or 104° F: A high body temperature that reaches or exceeds 40° C (104° F) can be indicative of heat-related illnesses.

Throbbing headache: Intense, pulsating headaches can occur as a result of the heat.

Anxiety, dizziness, fainting, and light-headedness: These symptoms may arise due to heat-induced stress on the body.

Muscle weakness or cramps: High temperatures can cause muscle weakness or involuntary contractions known as cramps.

Nausea and vomiting: Heat-related illnesses can lead to feelings of nausea and vomiting.

Rapid heartbeat: The heart may beat faster than usual in response to the heat.

Rapid, shallow breathing: Heat-related stress can result in increased breathing rate with shallow breaths.

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IMD guidelines

The IMD has also issued provided guidelines to follow during high temperatures:

• Avoid going out in the sun, especially between noon and 3 pm, when temperatures are at their peak.
• Drink sufficient water regularly, even if you do not feel thirsty, to stay hydrated.
• Wear lightweight, light-colored, loose-fitting, and breathable cotton clothing. Use protective goggles, an umbrella/hat, and suitable footwear when going out in the sun.
• Avoid engaging in strenuous activities during high temperatures, particularly between noon and 3 pm.
• Carry water with you when travelling to ensure hydration on the go.
• If you work outdoors, use a hat or umbrella for shade and a damp cloth to cool your head, neck, face, and limbs.
• Never leave children or pets unattended in parked vehicles, as the temperature inside can quickly become dangerously high.
• Seek immediate medical attention if you faint or feel unwell.
• Use oral rehydration solutions (ORS) or homemade drinks like lassi, torani (rice water), lemon water, buttermilk, etc, to replenish fluids and electrolytes in the body.
• Provide shade and ample water for animals to drink to keep them hydrated and protected from the heat.
• Keep your home cool by using curtains, shutters, or sunshades. Open windows during the cooler hours of the night.
• Use fans and damp clothing to create a cooling effect, and take frequent baths with cold water.
• In case a person is affected by sunstroke, lay them in a cool place in the shade, wipe their body with a wet cloth, and frequently pour room-temperature water on their head to bring down their body temperature. Offer ORS, lemon sherbet, or other hydrating beverages. Seek immediate medical attention and hospitalisation, as heatstrokes can be fatal.

(Edited by Arkadev Ghoshal)