Combating heatwave: ‘Drink water but don’t overdo it. It can overload kidneys. Track urine output instead’

Dr SURANJIT CHATTERJEE, Senior Consultant, Internal Medicine, Indraprastha Apollo Hospital, Delhi, speaks to ANONNA DUTT about common heat-linked illnesses, explains why children and the elderly are most vulnerable in this season, and urges people to exercise indoors till the temperatures plunge.
Why Dr Chatterjee: He has worked in the field of general medicine for over 25 years, and has experience in treating both communicable and non-communicable diseases.
What is heat-related illness and how can we protect ourselves from it?
We mostly see cases of heat exhaustion, where people feel extremely lethargic after stepping out during the day. But the high temperatures may also lead to a heat stroke, where the body overheats to more than 40°C (104°F) resulting in damage to the organs and neurological dysfunctions. It can result in fainting, rashes etc.
The most important thing is to stay well hydrated, especially when out in the heat. Hydration can be in the form of water or something with electrolytes, such as shikanji. Also, thirst is not the only good indicator of whether you need to have more fluids. So, people must keep a track of how much water they are consuming. The thing that one should keep an eye on is the urine output, which goes down when a person is dehydrated.
Other than that, people must not wear dark-coloured, tight fitting, synthetic clothes when it is as hot as this. Light-coloured, cotton clothes are the best. Covering the head also helps.
As much as possible, people should stay indoors during extremely hot hours.

How much water or fluids should we consume? And, can people overdo it?
Yes, people can certainly overdo it. I have heard people talking about drinking water every 20 minutes. That’s not how it works. The amount of water intake depends on a person’s health.
An apparently healthy, young person should drink anywhere between 2.5 to 3 litres of water. Perhaps, an additional 0.5 to 1 litre of water can be had if they are out in the sun. Anything more, may overload the kidneys that have to work harder to flush out the extra water. Excess water may also lead to electrolyte imbalance, which can cause its own set of problems.
Then, there are persons living with a kidney or a heart disease, they should not overload themselves with water as it may result in fluid accumulation in the legs, abdomen, and chest, which can in turn lead to breathing difficulties. People with such chronic conditions have to drink anywhere between 1 to 1.5 litres of water throughout the day. However, this would depend on the condition of their organs. Anyone who is on fluid restriction should definitely get in touch with their physician to check how much water they should have.

Having electrolyte-rich fluid is a better option when people are out in the sun. Around two to three glasses of shikanji wouldn’t be a problem for a healthy person. Again, those with any comorbidities should keep an eye on what they are having, for example, diabetics should avoid ORS solutions because they are high in sugar content.
Which section is most vulnerable in this season?
Children below the age of 5 and people above 65 years are more vulnerable to the impact of heat. They must avoid stepping out during the hot hours, and if they have to, they must be extremely careful and stay well hydrated. However, the young, healthy people are not completely safe either. They mostly constitute the working population and are more likely to step out in the sun.
Also, anybody living with comorbidities such as cardiac diseases, diabetes, or thyroid is likely to feel the effect of sun exposure more.

Should people exercise in this season?
Exercising is not a problem; exercising when it is hot is. If people want to go out for a walk or a jog, they should either do it early in the morning between 5-6 am or in the evening after 7 pm. People should not do any physical activity between 10 am and 6pm when it is this hot.
And, if people can exercise indoors – if they have enough space at home or they can join the gym – then that is better than outdoor exercise.
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