Cold wave heightens risk of infections, affects patients with hypertension, heart ailments, caution doctors

With increased patient load due to cold wave conditions in the ongoing winter months, doctors are warning of heightened risk of infections (flu, pneumonia, other respiratory illnesses) that may trigger flare-ups of chronic obstructive pulmonary disease, and adversely affect patients with high blood pressure and heart ailments.

“Cold weather causes blood vessels to constrict, raising blood pressure and increasing the workload on the heart,’’ Sanjeeva Kumar Gupta, consultant, Department of Cardiology, C.K. Birla Hospital, Delhi, said.

Reducing physical activity, higher intake of salty foods, dehydration, and winter illnesses place additional strain on the cardiovascular system, Dr. Gupta added. Cold weather also triggers stress hormones, including adrenaline, which raise blood pressure and heart rate, he cautioned.

“During winters, the body’s sodium and potassium levels can fluctuate. Lower fluid intake and dehydration may lead to higher sodium levels. At the same time, changes in diet, use of diuretics, and eating fewer fruits and vegetables can cause potassium imbalance, especially in heart patients,” Dr. Gupta said.

Common seasonal respiratory illnesses, alongside stomach viruses such as Norovirus, often exacerbated by cold, dry air and indoor crowding, adversely impact vulnerable populations, stressing immune systems and increasing risks for chronic conditions, including asthma, heart disease, and dry skin.

“Maintaining adequate hydration (even with warm fluids), reducing consumption of salty/processed foods, and increasing consumption of potassium-rich produce (fruits/vegetables) helps prevent issues such as cramps, fatigue, and kidney stones, by supporting kidney function and electrolyte balance,” Pankaj Soni, principal director, internal medicine, Fortis Escorts Hospital, Okhla, said.

“Children under five years, especially infants, and adults over 65 years; people with chronic heart, lung, kidney, or liver disease; diabetes; and weakened immunity (caused by, for example, cancer therapy, the use of steroids), pregnant women, and people who are significantly overweight or obese are especially vulnerable,” Neetu Jain, senior consultant pulmonology, critical care and sleep medicine, Pushpawati Singhania Research InstituteHospital, said.

India is currently witnessing an early and ongoing intense cold wave, with temperatures falling 3°C to 5°C below normal across several States. Long-term government data show that the number of cold wave days has increased in several regions, including Jammu & Kashmir, Delhi, and Odisha.

A report by the National Crime Records Bureau, referenced in communications to governments of States and Union Territories by the National Human Rights Commission, states that 3,639 people died from exposure to cold waves between 2019 and 2023 in India, an average of about 728 deaths per year in this period. A 2021 study by The Lancet found that India faces a massive burden from non-optimal temperatures, with cold waves affecting vulnerable States, including Bihar and Uttar Pradesh, the most.

A paper titled ‘Spatial and Temporal Analysis of Cold Wave Incidences and Mortality in Indian States’ shows cold waves remain one of India’s deadly extreme climate events.

“A cold wave can have very harmful effects upon all kinds of organisms inhabiting the area, some of which are death and/or injury to livestock/wildlife, increase in caloric demand of the body, hypothermia in humans, and crop failure or death of plants,’’ the study, which reports a decrease in the number of deaths linked to cold wave conditions after 2015, states. Such fatalities can be reduced further by identifying vulnerable areas, and ensuring adequate supplies, including of food, drinking water, fuel, and medicines.