Heatwave Grips India, Uttarakhand May Get Rain Relief as Temperatures Soar

Added: 2026-05-24

[00:00:00]As the temperatures cross 45 degrees Celsius in many parts of India, the wet bulb temperature is witnessing a sharp dip to 35 degrees Celsius. This dip would be a catastrophic crisis as the human body is reaching near lethal temperatures. A wet bulb temperature of 35 degrees Celsius is widely considered the maximum theoretical upper limit of human survivability. 40 years back this stood at 42 degrees Celsius. Last year the wet bulb temperature remained 31 degrees Celsius for as long as 40 days.

[00:00:27]5 years back this lasted for 24 days.

[00:00:30]Means the duration is increasing by the year but the wet bulb temperature is decreasing. This is the lowest temperature at which the body can cool itself by sweating. If the temperature is 40 degrees Celsius and the winds is dry, then the body can save itself from heat through sweat. But if the temperature is 35 degrees Celsius and the moisture is high, then the cooling system in the body begins to fail.

[00:00:50]Harvard South Asia Institute released a white paper asking a question, how hot is too hot? Researchers say that the human body can only handle so much heat before it can no longer cool itself and that limit is below a wet bulb temperature of 35 degrees Celsius. Above this limit even a young healthy person resting in the shade with access to ample drinking water and skin fully coated in sweat would experience a continual rise in core temperature leading to death from heat stroke within hours. To discuss more on this, I'm being joined by Dr. K.J. Ramesh, former DG IMD and Padma Shri Dr. Sanjeev Bagai, chairman of Nephron Clinic. Both of you welcome on the broadcast. Thank you so much for joining me.

[00:01:30]Uh let me first go to Padma Shri Dr. Sanjeev Bagai, chairman of Nephron Clinic. Uh Mr. Bagai, the situation is very grim. We can see that the heat wave is causing a lot of problems in everybody's lives. For the viewers, how can one tackle this wet bulb temperature and how hot is too hot for people in India because according to a study 3 38 million people are living in this condition where it might be difficult for them to cool their body itself.

[00:01:59]Good afternoon.

[00:02:01]So, I think living in a tropical country like India and when you're experiencing, especially in the northern parts of India, a rather prolonged summer for about 3 to 4 months.

[00:02:12]We as human beings almost take it as granted that it's going to be hot here.

[00:02:17]Garmi hai. And very often then the precautions which we need to take and the caution we need to take are inadequate.

[00:02:25]Now, when you're looking at an exposure, it's actually begins as a heat exposure in few hours of staring heat like what we are seeing now in Delhi NCR, it turns into heat exhaustion and then we get a heat stroke and then a patient can actually go into shock and even lose their life.

[00:02:42]Uh in the immediate response actually the body gives as a compensatory response, the muscle starts cramping, you have pain, you have weakness, you had you have rather like a brain fog, uh impaired brain function, uh more agitation, a lot of anxiety and with gradual fluid electrolyte imbalance the kidneys can get impacted and going into kidney failure. Of course, you have other cardio cardiorespiratory manifestations as hypertension, abnormal heart rates and so on.

[00:03:13]The carry home advice is that the people who are most at risk are children especially under the age of five, elderly beyond 60-65 and anyone who has comorbidities, especially if you had seizures in the past or you have a transplant organ transplant in the past, hypertension, diabetes, COPD, asthma need to be especially careful at this time of the year. Taking water alone is not adequate. We need to take adequate amount of fluid and electrolytes. So, you have to correct the body salts of what we lose. Remember when you are exposed for even couple of hours in this kind of heat, it can often will fatal.

[00:03:51]So, cover the exposed parts of the body.

[00:03:53]Please wear a sun hat, carry an umbrella that will protect you, but go out only if it's a must, especially after 11:00, 11:30 in the morning till about 4:00 or 4:30 in the evening. And the schools should close down because this is incompatible with life as far as the heat is concerned. And there is a lot of convection currents from the soil. So, if you stand too long in open air, it's not only the environmental temperature but the feet also gather the heat from the soil or the earth below. So, it's a double compounding effect as far as the body is concerned. And remember adequate amount of hydration and adequate amount of food intake, nutrition is important.

[00:04:35]Avoid very, very oily or heavy food. It becomes difficult to digest. Take lighter food, salads, fluids, and correct yourself with body salts. Over to you. Well, uh let me go across to Dr. K.J. Ramesh. Sir, how serious is this threat when cities are continue to record night temperatures that is above 30°C where it's a condition where a human body cannot itself cool down and cannot actually tolerate the rising heat and humidity?

[00:05:03]Uh there are two categories of extreme heat factor which you have just mentioned. When humidity is high along with the temperatures and dry winds and the sunshine solar radiation also. But when humidity is not that high, the dry heat now which is there over North India. So, there day and night temperature difference is reduction will add extreme heat factor.

[00:05:34]Uh that will give one kind of heat stress.

[00:05:37]And what we are talking about wet bulb global temperature impact is more on coastal cities throughout the year even above 28, 29° of centigrade temperature when high humidity is there, they feel like 35, 38 degrees temperature. So, that's where the extreme heat factor will continue. So, there are here we are talking about a two category of wet bulb temperature related impacts. In North India now we are seeing above close to 30 degrees night temperature, minimum temperature, and day temperatures are about 40 to 45.

[00:06:11]So, that's where the comes. North India wet bulb temperature effect will start happening after the monsoon comes over the Gangetic plains. That's where the humidity will come into the picture there. Till then it is a dry heat over there. But, in any case wet bulb temperatures any anything above 28 to 27 degrees temperature which will start impacting severe heat stress on human body.

[00:06:38]Well, that's okay. That's insightful. Let me go across to Dr. Bagai as well. Dr. Bagai, do you think that this is a silent uh climate emergency that India is witnessing right now because a 38 degree temperature in a humid climate is still better than 40 is worse than a 40 degree temperature in a dry climate.

[00:06:57]Yes, my colleague has brought out a very salient point. Relative humidity has a huge impact in your electrolyte and fluid loss from the skin and your body organs can dry up. Your vasculature can dry up and you can have a more intense impact as far as your fluid losses are concerned. So, it's both temperature, the duration of exposure, the type of exposure, and the relative humidity which causes overall cumulative toll on the body.

[00:07:27]But, the more important point is this is a part of the global climate change.

[00:07:32]This is a part of the environmental shift which is taking place. A lot of deforestation which has taken place in the in the outskirts of Delhi. And of course Delhi itself is is a landlocked area which is devoid of water itself. So, overall we need to preserve the environment. I've always been a championing the cause of maintaining the green cover because that's something which will keep us cooler in these months.

[00:07:59]But of course precautionary warning to all the citizens that you must take adequate care. Don't send children to the park in the afternoons or in early evenings. Wait for the sun to go down a little bit and make sure that the children are adequately hydrated. My real concern is when children play they lose a lot more because they breathe double as fast. They tend to exhaust themselves a lot quicker. So, we need to be more cautious and specially the elderly with comorbidities, hypertension, diabetes need to take special care and precautions that they don't go into a stage of dehydration or specially sodium loss. Right. Dr. Ramesh, uh quickly, do you think that the heat action plan that we have in existence right now is enough and what is your advice to our viewers in this extreme heat?

[00:08:48]Heat action plans are there only to take care of extra sufficient beds, extra beds in the hospitals for morbidity heat heat related morbidity cases. Emergency care is required for them. And another important factor is providing access to safe and clean drinking water to all citizens particularly in particularly in exposed areas where people are living in houses with the tops of asbestos sheets and the metal sheets roofs. So, there the heat stress impact will be much more on them. And then continuous uninterrupted power supply becomes important. If the power supply is not there when heat is high and impact of the heat stress will be much more. And more importantly now the way we used to establish night shelters during winters, rain baseras in Delhi, now we need to establish cool shelters in within the clusters where exposure of the people is pretty high. And Chennai has started it and Chennai Delhi also started experimenting with couple of cool shelters now. And it has to be now thinking broad thinking is required, implementation is required as a part of heat action plans to establish cool cool cool roofs and cool shelters for the people.

[00:10:20]Well, thank you so much Dr. K.J. Ramesh and Dr. Sanjeev Bagai for joining me on the broadcast with those meaningful insights.