Produced by: Tarun Mishra Designed by: Manoj Kumar
The India Meteorological Department (IMD) reported on Wednesday that temperatures in Delhi reached an unprecedented 52.3°C. Mungeshpur, a suburb of Delhi, also recorded its highest temperature ever, surpassing 50°C for the first time in the city’s history. This extreme heat event is part of a broader trend of rising temperatures across the region.
The IMD has issued a severe heat wave forecast for the coming days, predicting “heat wave to severe heat wave conditions” in most parts of Punjab, Haryana, and Chandigarh, many areas of Delhi, Uttar Pradesh, and Rajasthan, and isolated regions in Jammu & Kashmir and Himachal Pradesh. The forecast also indicates that warm nighttime temperatures will persist in several areas, providing little respite from the daytime heat.
Human body cells begin to die at temperatures between 46-60°C. At around 50°C, irreversible damage starts as proteins within the cells coagulate. The body’s first response to extreme heat is sweating to cool itself down, which can lead to significant water loss and dehydration. If the body fails to cool itself sufficiently, it can result in heat cramps, heat exhaustion, or even heatstroke.
The human body’s average temperature is 36-37.5°C, and it maintains this temperature primarily through sweating. Heavy breathing and an increased heart rate also help expel heat. However, excessive sweating due to high temperatures can lead to dehydration. If the body cannot cool down effectively, it can suffer from heat-related illnesses such as heat cramps, heat exhaustion, and heatstroke. Dr. Shuchin Bajaj, founder and director of Ujala Cygnus Group of Hospitals, noted the increased risk of dehydration and other health issues during heatwaves.
Heat stress, acute kidney injury, and worsening heart diseases are common during heatwaves. More than 6,000 people in India have died due to heatwaves in the last decade. Dr. R.R. Dutta, head of internal medicine at Paras Hospitals in Gurugram, reported receiving 20-25 heat-related cases daily, affecting a wide age range from children to the elderly. Blue-collar workers, including farmers, construction workers, and delivery personnel, are particularly vulnerable as they often work outside in the sun.
The World Health Organization (WHO) estimates that climate change will cause approximately 250,000 additional deaths per year from malnutrition, malaria, diarrhoea, and heat stress between 2030 and 2050. The extreme temperatures during heatwaves exacerbate existing health conditions and increase mortality rates, particularly among older adults and those with pre-existing health conditions.
Extreme heat impacts the body’s ability to regulate its internal temperature, worsening chronic conditions such as cardiovascular disease, respiratory disease, cerebrovascular disease, and diabetes-related conditions. Increased temperatures can lead to an imbalance between high cardiac oxygen demand and a compromised cardiac oxygen delivery, resulting in cardiac ischaemia, infarction, and ultimately, cardiovascular collapse. According to a study published in The Lancet, older adults are particularly vulnerable to cardiovascular events during heat extremes.
Birds are at risk of lethal hyperthermia if environmental temperatures exceed their heat tolerance limits. They can also suffer from lethal dehydration if the water needed for evaporative cooling surpasses their dehydration tolerance limits. Research published in the Proceedings of the National Academy of Sciences highlights these risks. Dogs are similarly vulnerable to heat strokes, which can lead to seizures and unconsciousness, as per a report by Kansas State University. Livestock also suffer from production losses and impaired function due to heat stress, necessitating shaded areas and adequate water supply to mitigate these effects.
The rise in temperature has led to an increase in fire incidents. Over 500 forest fires were reported in Himachal Pradesh in April 2022, damaging 3,575 hectares according to The Hindu.