Is the cold wave in north India causing heart attacks? The science explained

A killer cold wave has gripped parts of north India. The India Meteorological Department (IMD) has issued a red and yellow alert in several parts such as Uttar Pradesh, Punjab, Haryana, Chandigarh, Rajasthan, and Uttarakhand. The National Capital region have been witnessing some of the coldest days in history over the past week as a blanket of fog engulfed the Indo-Gangetic Plain, blocking out the warming sun and keeping daytime temperatures close to nail-biting levels.

As per a weather expert, parts of north India are likely to witness a temperature of -4 degrees Celsius and a maximum of 2 degrees Celsius. The cold wave conditions have also resulted in deaths. At least 98 people reportedly died in Uttar Pradesh’s Kanpur because of heart and brain strokes in a week, reported news agency IANS.

An increase in blood pressure in the cold and blood clotting can be fatal for the heart and the brain. “The cold causes the blood vessels to contract, also known as vasoconstriction and it leads to high blood pressure. Heart attacks occur due to blood clot formation in coronary arteries. The fibrinogen levels in our body increase up to 23 per cent during winters. The platelet count increases as well, which causes the blood to form clots and lead to a heart attack,” Dr Manoj Kumar, a senior cardiologist from the Max Hospital, New Delhi, told ANI.

Hypothermia is caused by prolonged exposure to very cold temperatures as the human body begins to lose heat at a faster pace than it is produced, according to the US Centers for Diseases Control (CDC). When the human body’s internal temperature drops to below 35 degrees Celsius, it will experience the symptoms of mild hypothermia. In case of severe hypothermia (below 28 degrees Celsius), the body may be unconscious and may not seem to have a pulse or be breathing. It will be dangerously close to death.

In the state of moderate hypothermia (32 to 28 degrees Celsius), the body experiences confusion, agitation, lethargy, and sometimes even hallucinations. From 35 degrees Celsius to 32 degrees Celsius, the human body might suffer from impaired judgement, amnesia, and hyperemia (when the blood flow changes to different parts of our body).

Medical News Today explains hyperemia occurs when “excess blood builds up inside the vascular system, which is the system of blood vessels in the body.” The blood flows from the extremities to the core and vital organs to keep them warm and in a state of homeostasis. Because of this, the liver, heart, lungs, and spleen get more circulation, while fingers, toes, nose, and earlobes receive less blood circulation, making them colder.

To stay warm, the human body shivers and undergoes vasoconstriction, meaning the blood vessels contract and increase blood pressure and circulation. This can also lead to hypertension in several individuals. Exposure to cold temperatures for a longer period can use up the body’s stored energy, leading to lower body temperature. This can also affect the human brain, “making the victim unable to think clearly or move well,” or experience trouble in speaking.

When the external temperature falls, the human body generates heat to compensate for the difference. While if the external temperature rises, the body releases the heat by sweating to cool itself. This is called thermoregulation. This is why the human body sweats in the heat and does not in the cold.

Notably, human bodies are remarkably capable of surviving temperature changes, however, the body cannot fight biology and nature. The human body can only warm or cool itself to a certain extent.  When the defence mechanisms begin to suffer, there can be some concerning effects, as per CDC.

Several health issues like bone, joint, and muscle pain, cough and cold, respiratory diseases such as bronchitis, skin problems can arise when a human body is exposed to lengthy cold conditions. Frostbite can permanently damage the body, and severe cases can lead to amputation (removing the affected body part).

According to CDC, when it is very cold outside, stay indoors. Wear several layers of loose-fitting clothing and cover yourself in blankets. Taking Vitamin D supplements is recommended as a deficiency can lead to a heart attack. Avoid a morning walk before sunrise. Ensure your head is covered well, advises Dr Kumar.

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