Extreme temperatures can have a significant effect on a person’s health. Take the warmest season of the year, for instance. Exposure to excessive heat puts extra strain on the heart because your body must work harder to keep its core temperature normal.
So, apart from causing sweat and fatigue, the soaring mercury levels during summer can even cause blood pressure variation.
Dr Divakar Bhat, consultant, cardiothoracic and vascular surgery, Aster RV Hospital, Bangalore, says that severe temperatures, particularly hot weather, are bad for heart health, and people with existing heart conditions are more likely to experience dehydration, electrolyte imbalance, muscular cramps, arrhythmias and hypertension.
Extreme high temperatures can also worsen existing heart conditions, say experts.
Heatwaves and heart health
The summer is yet to peak, but the India Meteorological Department has already issue heatwave warnings for Maharashtra, Odisha, Tamil Nadu, Andhra Pradesh, West Bengal, Jharkhand, Bihar and Telangana. These states are likely to see a three-to-four-degree Celsius rise in temperature in early May.
The mercury crossed 43 degree C in many places in the past few days: 43.7 in Solapur, Maharashtra (April 28), 44.6 in Bhubaneswar, Odisha (April 29), 42 in Erode, Tamil Nadu (April 29), and 45.6 in Nandyal, Andhra Pradesh (April 29).
High temperatures and heatwaves can lead to increased heart disease, stroke, heart failure and arrhythmia due to dehydration, increased metabolic demand and systemic inflammatory responses, according to a 2023 study that looked at a data set from 27 countries.
This makes it all the more important for people to be aware of symptoms of heat stroke like hot, red, dry or damp skin, rapid and strong pulse, altered mental status, confusion or disorientation, nausea, vomiting, dizziness, fainting and loss of consciousness.
Heart health during summer vs winter
In some cases, blood pressure medication doses may have to be altered during extreme summer. Hence, consulting a doctor is necessary.
“If someone on medications for blood pressure continues taking the same dose in summer, their blood pressure might [drop too] low and that might cause dizziness or even loss of consciousness,” says Dr Varun Bansal, consultant, cardiology and cardio thoracic surgery, Indraprastha Apollo Hospitals, New Delhi. “So, it is important to see a doctor as seasons change, to confirm if there is a need to change medications. When the temperature changes from winter to summer, the heat outside the body increases, causing more sweat and loss of water. This causes dehydration.”
In winters, people prefer staying indoors and consume less water; physical activity is also less. But if the same routine is continued in summer, it can turn problematic, say doctors.
“Our body generates heat during winters, but not during summers,” adds Dr Bansal. “One must note that the metabolic changes that occur during summer can impact heart health, especially for people with existing heart conditions.”
How plasma regulates body temperature
Plasma, the liquid component of blood, has a role to play in maintaining body temperature. Reduction of plasma through sweating, which is more common in the summer, affects the heart.
Too much sweating leads to a reduction in the amount of intravascular fluid, plasma and blood cells because of dehydration. “This causes health risks like reduced blood volume, reduced urine output, increased load on the heart and increased load on the kidneys,” adds Dr Bansal.
Physical activity during heatwaves
It is also important to maintain your body weight by regularly exercising during summer. Dr Bhat suggests avoiding extreme or strenuous physical activities when the temperature is unusually high as this could result in severe dehydration and sweating, which can lead to electrolyte imbalance, muscle cramps and arrhythmias (irregular heartbeat).
Experts recommend exercising early in the morning or late in the evening in summers and avoiding physical activity between 11am and 4pm. If you are free to exercise only during this time, make sure to do so indoors, in a controlled environment, adds Dr Bansal.
Stay hydrated for good heart health
During summer, high temperature and humidity can lead to dehydration and sweating. So, it is essential to maintain proper hydration. Experts say you should consume at least two to 2.5 liters of water every day. “Since we also lose sodium in sweat, it is important to have electrolytes like lime water and ORS, and not just plain water,” says Dr Bansal.
He suggests that children should have one or two glasses of water after coming back from play during the summer holidays. “Staying out under scorching sun in the afternoon can get tiring,” he adds. “Adults who also are out all day can come home and have at least two glasses of water.”
Dr Bhat says having fruit juices and buttermilk helps keep hydration at bay. He recommends having food rich in water content (such as cucumber, watermelon, orange, strawberry, pineapple, peach, broccoli, bell pepper and celery) and avoiding spicy and high-fat foods.
Dr Bansal adds that people on water-intake restrictions face difficulties during summer and must be extra cautious about quenching their thirst. “People with low heart function or heart disease are asked to restrict water intake as it can cause excess load on the heart,” he said.
Heart health precautions during extreme heatwaves
- Avoid exposure to extremes of weather or sudden changes in temperature. “Sometimes we sit in an air-conditioned environment and then suddenly go out in the sun where there is extreme heat. This is harmful for one’s heart health,” says Dr Bansal.
- Adhere to medications. One should take medications as per the doctor’s advice. “People should not keep taking the same medications repeatedly, even with the changes in temperature,” he adds.
- Avoid synthetic clothes during summer as they trap heat, don’t absorb sweat and can cause skin irritation. Dr Bhat recommends wearing cotton and loose clothing. He also suggests avoiding dark-coloured clothes because they tend to absorb more heat.
Takeaways
Keep in mind that excessive heat puts extra strain on your heart. Consume at least two to 2.5 liters of water every day to prevent dehydration. Avoid exercising during the day when it is too hot, and instead work out early in the morning or late in the evening. Chose cotton clothes. Consult with your doctor if you are on medications for blood pressure.
