As Delhi continues to reel under a cold wave, doctors at AIIMS Delhi have cautioned that extreme winter conditions can worsen chronic illnesses and adversely affect vital organs such as the heart, kidneys and lungs.

On Monday, the national capital recorded a maximum temperature of 20.6 degrees Celsius — 0.7 degrees above normal — while the minimum temperature dropped sharply to 3.2 degrees Celsius, which was 4.2 degrees below the seasonal average.

Highlighting the impact of cold weather on heart health, Dr. Rajiv Narang, Head of the Department of Cardiology at AIIMS, said that extremely low temperatures directly influence blood pressure.

"During winter, blood vessels get constricted and also there is less water intake, which negatively affects blood flow and leads to an increase in blood pressure. Also, the consumption of salty and processed food rises during this time. All this combined can cause the blood pressure to climb, increasing the risk of heart attacks," he said.

Dr. Narang further advised people to regularly monitor their blood pressure during winter, adding that this can be done at home using BP machines. He also stressed the importance of staying well hydrated despite reduced thirst in cold weather.

Meanwhile, Dr. Sandeep Mahajan, a professor in the AIIMS Department of Nephrology, explained how cold weather affects kidney health by pointing out that severe cold spells often cause blood pressure to rise. Since many patients with chronic kidney disease (CKD) already suffer from hypertension, winter months often see further elevation in blood pressure levels.

"Maintaining strict blood pressure control is crucial for decelerating the progression of kidney disease. Consequently, individuals with CKD should diligently monitor their blood pressure throughout the winter and seek medical consultation as needed to optimise their blood pressure management," he said.

Dr. Mahajan encouraged patients to remain physically active through indoor activities such as yoga, which help regulate blood pressure and blood sugar levels when outdoor exercise becomes difficult due to cold weather. He further advised CKD patients to be cautious with winter diets.

"For individuals with CKD, the consumption of seasonal fruits and vegetables, including oranges and spinach, should be discussed with a dietitian or nephrologist. This is due to the potential for these foods to increase potassium levels, which could pose a life-threatening risk to these patients. Furthermore, adequate hydration is particularly important for patients with renal cystic and stone disease," Dr Mahajan advised.

Given their vulnerability to infections, he recommended that high-risk patients receive influenza and pneumonia vaccinations.

Meanwhile, Dr. Sanjeev Sinha, professor in the Department of Medicine at AIIMS, spoke about the impact of cold weather on respiratory health.

"Cold air exposure can lead to tightening and narrowing of the airways causing bronchospasm, and this can cause exacerbation in patients with bronchial asthma and Chronic Obstructive Pulmonary Disease (COPD). It can also lead to pneumonia in elderly people," he stated.

He added that cold wave conditions often trigger upper respiratory tract infections, leading to symptoms such as nasal discharge, sore throat, dry cough and fever. Winter pollution further aggravates respiratory problems, particularly among COPD patients.

Dr. Sinha advised vulnerable individuals to take adequate precautions, including staying indoors as much as possible, wearing multiple layers of warm clothing, using masks when stepping outside, and ensuring proper coverage of the head, ears, hands and feet to protect against extreme cold.