By Ritika Sakhuja and Prathiba Raju
New Delhi: Climate change is the biggest health issue, particularly the impact of extreme heat conditions and the year-on-year increase in temperatures in India, is a major contributing factor to hundreds of deaths and widespread health impacts.
According to a Lancet study, India saw a 55 per cent increase in deaths due to extreme heat between 2000-2004 and 2017-2021. The study also noted that excessive heat also led to a loss of 167.2 billion potential labour hours among Indians in 2021. Healthcare experts warn that heat exposure can exacerbate existing medical conditions and increase the severity of Non-Communicable Diseases (NCDs) and infectious diseases.
Temperatures soaring at unusual levels in some places of the country, and substantial deviations from expected normal temperatures from this time of the year are also being reported from some states and districts, informed Rajesh Bhushan, IAS, Secretary, Ministry of Health and Family Welfare (MoHFW) in his recent letter to the chief secretaries of all states/UTs. ETHealthworld spoke to medical experts about the repercussions of prolonged exposure to high temperatures and how it aggravates NCDs and infectious diseases.
Heatwave enables NCD prevalence
The weather tends to have a very strong impact on overall health. Rising temperatures can exacerbate pre-existing medical conditions as they negatively influence human health and overall well-being. “When the earth’s surface temperature rises, these changes increase the danger of human survival and certainly increase the prevalence of various NCDs, such as cardiovascular disease, respiratory health, mental disorders, accidents, and malnutrition,” said Dr Anil Venkatachalam, Neurologist, Zen Multispeciality Hospital, Chembur.
Numerous studies have shown that heatstroke is associated with an increased risk of cardiovascular diseases including ischemic heart disease, heart failure and atrial fibrillation. “Rising temperatures can have an adverse effect on people suffering from a blockage in the heart, high blood pressure, or depressed heart pumping. Hydration is important because in certain cases, there can be issues of a heart attack,” said Dr Abhijit Joshi, Consultant and HOD, Cardiology, Manipal Hospital, Baner-Pune.
In addition to cardiovascular complications, the neural function of the body also undergoes impairments due to extended heat exposure. “Certain diseases which worsen during summer months are headaches, vertigo and migraines. Also due to dehydration, there is an increased risk of vascular events such as strokes and venous sinus thrombosis. Certain epilepsies and patients with multiple sclerosis have an increase in the number of attacks during the summer months. Parkinson’s patients also have an impairment of thermoregulatory mechanisms and are at an increased risk of developing heat strokes,” illuminated Dr Venkatchalam.
He added, “Heat stress can alter operators’ cognitive function owing to discomfort, cognitive weariness, disruptions, and unconsciousness. Hyperthermia due to heat exposure frequently causes brain and organ damage.”
Abrupt weather change spurt cases of viral infections
India experiences a high incidence of infectious diseases during the summer months, particularly in the northern and eastern parts of the country. As the weather transitions from one season to the other, viral cases generally witness an incline during these phases throughout the year. As winter is fading and summers are embarking early, hospitals across the country are reporting a steep rise in cases of viral fever, cold and cough, and severe throat infections.
Relaying the incidence of infections plaguing the masses, Prof Dr SK Chhabra, Head, Pulmonary, Sleep and Critical Care Medicine, Primus Hospital said, “We are experiencing a 90 per cent surge in terms of patients reporting viral infections in our OPDs as the weather is changing rapidly making people susceptible to various infections. Viral fever, cold and cough, and severe lung allergies like bronchitis are being reported majorly in the patients visiting the hospital.”
Elucidating on the viral diseases which peaks during summer season, Dr Laxman Jessani, Consultant, Infectious Disease, Apollo Hospitals, Navi Mumbai said, “Diseases such as dengue fever, malaria, chikungunya, and typhoid are also common during this time. We have seen an increase in respiratory viral infections especially when there are sudden climatic changes from cold to heat in addition to foodborne illnesses like typhoid, diarrhoea, and shigella due to poor hygiene and water shortages.”
Doctors also informed that the rise in the number of patients complaining of viral infections, and chest congestion reflects how seasonal change is gravely impacting the health conditions of people. Added that pollution is also playing a pivotal role in multiplying the patient numbers impacted by viral infections.
“Patients having chronic ailments like asthma have to be extra cautious during such weather transitions as it can trigger severe respiratory issues and asthma attacks. During this time, even a minor respiratory problem must be reported to a pulmonologist or a physician to reduce the risk of escalating the problem,” advised Dr Chhabra.
Urging the need to address climate change to mitigate the impact of infectious diseases during summer in India, Jessani said, “The impact of gruelling heat waves can cause complications such as dehydration, electrolyte imbalances, heat exhaustion, heatstroke and decrease immunity which makes one more susceptible to catch infection.”
Beware of common medications
Doctors expressed that heat-related illnesses when combined with certain common medications can cause adverse effects, and in extreme cases, prove fatal. “Senior citizens with comorbidities such as diabetes or heart problems, who use heavy medications like high doses of diuretics, are at extreme risk if they go out in the sun. They’re likely to suffer heat-related complications of heatstroke and heat exhaustion, especially if they are typically dehydrated,” informed Dr Jessani.
Stating that people are often not aware of their daily habits that can aggravate an already dangerous situation of heat-related illnesses, Dr Manjusha Agarwal, senior Consultant- Internal Medicine, Global Hospitals, Parel Mumbai, warned, “Psychiatric medications, cardiac medications like diuretics, and blood pressure medications could increase your body temperature if taken in high dosages. If you are going up in the sun there can be a problem of increased sweating and low blood pressure, and simultaneously if you’re taking blood pressure medication there could be a drop in blood pressure.”
As high heat causes the body to lose water rapidly which in turn lowers the body’s blood pressure leading to feelings of lightheadedness and lethargy, patients taking medications that aid in lowering blood pressure should exercise extra caution.
“Patients who have undergone angioplasty or bypass surgery for the heart, are given blood thinner medicine. If they are exposed to excessive heat, there can be excessive sweating and changes in the viscosity of the blood. Hence, the blood becomes thicker causing major issues of ischemia (low blood pressure-related issues) in the heart. Heart patients must also consult their doctors for diuretic doses as they help produce more urine. People who are on this medication can suffer from dehydration during extreme heat, and can lead to fatal consequences,” said Dr Joshi.
Naming common medications that can cause such complications, Dr Aniket Mule, consultant internal medicine, Wockhardt Hospitals, Mira Road, shared, “Prescribed medications which are taken by cardiac patients like diuretics, may make them devoid water so that their heart functions well. Diuretics like Dytor, Torsemide and Rosemide are used to make patients dehydrated by causing more taurine to be released so blood pressure lowers and heart pumping becomes more efficient. Along with that some antihypertensives like chlorthalidone hydrochlorothiazides, also work in the same fashion and can cause dehydration.”
Hydration is key
Heat-related deaths have been at an all-time low in the last few years owing to the increase in preventive measures, access to affordable healthcare, and infrastructural development. However, the increase in the cases of NCDs aggravation and viral infections proves that tackling heatwave is still an ongoing battle in India.
It is common knowledge that hydration is one of the most important tools in the arsenal against heat-related illnesses. As per NPCCHH’s public health advisory, hydration is key to protecting oneself from heat-related exertions. NPCCHH advises drinking ample water whenever possible, using ORS, consuming homemade drinks like lemon water, buttermilk, and fruit juices with some added salt, and eating seasonal fruits and vegetables with high water content.
Elucidating the consequences of dehydration, Dr Agarwal alerted, “You have to have a good water intake of at least three litres per day, for people who have no restrictions on their water intake. This is a season when we see a lot of kidney stones. Many patients come over with renal colic. Dehydration can lead to aggravation of kidney failure. People who have a history of renal kidney stones should have at least three to four litres of water a day if permitted by their doctor.”
However, experts informed that drinking too much water can also be risky. Typically what has been suggested is somewhere between two and a half litres for average females and three to three and a half litres for an average size male, but people often overdo this.
“When you drink excessive water, it can lead to dilution of your blood and a subsequent drop in sodium causing nausea, vomiting, and in severe cases convulsions and loss of consciousness. Additionally, we often ask people with kidney disease and heart problems to take water as per their physician’s advice because they do not have good urine output or their heart is weak. So the heart and kidney would not tolerate increased water intake,” said Dr Agarwal.
“If we intoxicate ourselves with water the first thing that will happen is that the sodium will go down. We call it dilutional hyponatremia, and it’s common for patients with kidney disease or heart disease where the body does not incorporate water efficiently. The patient may experience giddiness, forgetfulness, confusion, generalized weakness, and vomiting. But if hyponatremia worsens, the patient may land up in a coma or may have seizures. That’s why we advise our cardiac patients to limit their water intake to 1.2 to 1.5 litres,” concluded Dr Mule.
Doctors warn that climate change-induced illnesses will pose a detrimental threat to health and the best way to protect from debilitating heat, is one’s own diligent proactiveness. Urged the general population to be aware of heat-related complications and the warning signs of heat-related illnesses, and advised the masses to keep themselves hydrated and protected from the blazing temperature.