How to keep pets cool without AC: the Indian flat in a power cut, hour by hour

Why an Indian flat keeps heating after the sun goes down

An Indian flat keeps heating after sunset because concrete stores the day's heat and gives it back slowly, and the measurement exists: across 50 low- and middle-income homes in Chennai, in Tamil Nadu, logged from October 2025 to April 2026, indoor temperature peaked at 8 and 9 pm at nearly 34.7 C, a delayed surge the researchers attribute to concrete walls and floors releasing heat they had stored since morning.

Those homes rarely dropped below 31 C at any hour, often stayed above 34 C for hours after sunset even in winter, and sat at 33.8 C to 34 C in the early morning, with relative humidity above 75 percent throughout. The report's own summary of that curve is the sentence worth keeping: the diurnal profile shows a compressed temperature range with limited fluctuation, meaning indoor environments do not experience meaningful cooling at any point during the day. Nearly every one of the 50 homes had a concrete roof, and the split by income was absolute: every high-income household had an air conditioner, every low-income household had only a ceiling fan.

The same pattern appears in the one open dataset that covers Indian homes with instruments rather than impressions. Tasgaonkar and colleagues installed 206 indoor data loggers across five low-income South Asian sites, three of them Indian, in Delhi and in the Yavatmal and Jalna districts of Maharashtra, and their finding is plain: indoor temperatures generally follow outdoor temperatures during the day, but houses cool down slower during the evening and night, so mean indoor temperatures exceed those measured outdoors. At night, they write, indoor temperatures are generally higher than outdoor temperatures as heat is trapped inside the houses and within the built-up infrastructure in densely populated neighbourhoods. Their urban households were selected on two criteria, one of which was the absence of any electric air-conditioning device, so this is a measurement of exactly the home this page is about.

The rural Indian figures are the blunt end of the same physics. In Wardha district in the Vidarbha region of Maharashtra, a census survey of 700 households covering 2,672 people, with indoor temperature logged from 1 March to 30 June 2022, recorded a highest indoor temperature of 40.0 C in a tin-roof house, while cement-slab houses recorded an average of 38.5 C. Eighty percent of those 2,672 people, 2,136 of them, reported at least one heat-related symptom. Nobody asked the animals.

The one piece of good news about living in a flat

A flat warms more slowly than a house does, and the modelling says by how much. Simulating a five-day blackout across 800,000 residential buildings in three United States cities, Stone and colleagues found the greatest indoor heat in one-storey, single-family houses and average heat index values almost 4 C lower in apartment buildings, with the additional exposure in a one-storey house relative to a flat averaging 3.9 C. Their explanation is structural and transfers directly to an Indian building: shared walls between units are not exposed to solar radiation, a larger interior air volume increases heat capacity, and higher average insulation dampens the rate at which a unit warms after a power outage. That is a model, in American housing, and this page labels it as one. What it supports is a direction rather than a number: the middle floor of a block, with neighbours on both sides, is the slowest room in the building to heat up, and it is where the animal should be.

When the cut comes, and why that hour is the worst one

The cut comes in the evening, which is the hour the flat is hottest, and both halves of that sentence are published. The India Residential Energy Survey's own conclusion names outages in the evening hours and during times of peak demand as the gap still to be closed, and the Chennai loggers put the indoor peak at 8 and 9 pm Climate Trends, Nighttime Thermal Stress…. Nobody has previously put those two findings in the same sentence, and the sentence is this page's reason for existing.

Start with the scale. The India Residential Energy Survey covered nearly 15,000 households in 1,210 villages and 614 wards across 152 districts in 21 states, and found an average Indian household receiving 20.6 hours of grid supply a day, 22 hours in urban areas against 20 in rural ones. Seventy-six percent of households faced unanticipated supply interruptions, two-thirds of rural and two-fifths of urban households faced outages at least once a day, and the report's conclusion records that even in urban areas unscheduled outages last up to 12 hours. Delhi, Kerala and Gujarat held slightly over 23 hours of average supply, while households in Uttar Pradesh, Jharkhand, Haryana, Assam and Bihar faced the longest outages.

Now the official figure, which looks like a contradiction and is not. The Ministry of Power's year-end review for 2025 reports energy shortages at the national level reduced to a mere 0.03 percent in FY 2025-26, down from 4.2 percent in FY 2013-14, with urban areas now enjoying up to 23.4 hours of power supply. Both numbers are honest and they measure different things. The 0.03 percent is unserved energy across the national grid; load shedding at your distribution transformer, a blown feeder fuse and a local fault are not in it. The 23.4 hours is an average, and an average that good still leaves 0.6 hours a day unaccounted for, which is one unscheduled 12-hour cut every twenty days. That is our arithmetic on the Ministry's own figure, and it is the cut that matters to an animal shut in a flat. Plan for the cut, not for the average.

What that means for the eight-hour cut

To plan for an eight-hour evening cut, work backwards from the hour the flat peaks rather than from the hour the sun is strongest. On the Chennai curve, a cut that begins at 4 pm runs through the 8 to 9 pm peak and ends near midnight, with the indoor temperature still at 33.8 C to 34 C by early morning. Nothing in that window gets easier on its own. The afternoon is the hour people watch for; the evening is the hour the building hands its heat back, and in a flat with no air movement it is the hour an animal has no answer to.

What actually cools a dog with no fan, in order of effectiveness

What actually cools a dog is water on its skin with air moving across it, and the Royal Veterinary College states the method precisely: pour water of any temperature that is cooler than the dog over it, and combine that with air movement from a breeze, a fan or air conditioning. With no electricity you keep the first half of that instruction and have to find the second half somewhere else.

Two details inside that sentence do most of the work. The first is where the water goes. Put it on the thin-haired undersides, the belly, the groin, the armpits and the paw pads, where blood runs close to the surface, rather than on the back. A veterinary clinic page on outages gives the same list, damp towels on the belly, paws or neck, and the American Kennel Club's own advice is to spray the underside of the body, the groin where the hair is less dense, and the bottoms of the feet American Kennel Club. The second is that water sitting on fur with still air around it is doing very little. Evaporation is the engine and air movement is what drives it.

That is why the fan matters more than any product in the house, and why its absence is the whole problem. Here the India Meteorological Department supplies the warning nobody applies to animals: on high-temperature days the surface wind gets heated in contact with the land, and when that hot wind reaches a body it tends to increase the body's temperature rather than lower it. Air moving over a dry animal in a 38 C room is moving heat towards the animal. Air moving over a wet animal in the same room is removing it. Wet first, then ventilate. Never the other way round.

How much that buys you depends on which Indian city you are in, because evaporation is limited by what the air will still accept. Wet fur in the dry inland air of Delhi or Ahmedabad evaporates fast and takes real heat with it. The same wet fur in Mumbai, Chennai or Kolkata in June, in air the Chennai loggers recorded above 75 percent relative humidity, evaporates slowly and buys far less. The India Meteorological Department states the principle for people in the same document: high relative humidity leads to a slower evaporation rate and so reduces the efficiency of the body's cooling mechanism. Bengaluru and Pune are the exception at both ends, with less heat to shed and more room to shed it into. The wet-bulb depression by city and by month, which is the number that actually decides this, is published on cooling vests and summer gear in India.

One popular Indian shortcut deserves naming, because the figure attached to it has no source. The page holding position one on Google India for this query tells readers that a DIY evaporative cooler made from a wet towel hung over a fan can lower the cage temperature by 3 to 4 degrees C, and gives no study, no measurement and no method behind that number. The mechanism is real and it is how a desert cooler works. The number is somebody's estimate, it assumes a working fan, and in Mumbai or Kolkata air at over 75 percent relative humidity the same arrangement has much less water it can shed.

Airflow when there is no fan

To move air with no electricity, open the flat rather than the room. Cross ventilation needs two openings on different walls, so a single window in a single bedroom moves nothing however wide it is open; the front door propped to the stairwell and a window on the far wall will. The India Meteorological Department's own household instruction is to keep your home cool, use curtains, shutters or sunshade, and open windows at night. Draw the curtains on the sun-facing side by mid-morning and open everything after dark, in that order, because a curtain drawn at 2 pm is stopping heat arriving while a window opened at 2 pm is letting it in.

One Indian caveat belongs with that advice and is almost never attached to it. In a north Indian winter and through the evening traffic peak in any large city, the air you are inviting in carries the street's particulate with it, and what that does to a dog's airway is set out in air pollution and your pet in India. In the pre-monsoon months this is a smaller problem than the heat, and the honest instruction is to open the windows and accept the trade. Through the monsoon and the post-Diwali weeks it is not, and the timing of when to air a flat belongs on that page.

The other heat source still working during a cut

The gas stove does not go off with the power, and the IMD's own don'ts include avoiding cooking during peak hours and opening doors and windows to ventilate the cooking area adequately. In a one- or two-room Indian flat the kitchen is not a separate climate. An hour of cooking during an afternoon cut raises the temperature of the room an animal cannot leave, and it is the one heat source in the flat you are still adding voluntarily. Cook before the cut or after it.

The order to do it in, in the first ten minutes of a cut

To use the first ten minutes of a cut well, work from the room outwards to the animal, because the room takes longest to respond. The six steps below are in that order.

1. Open the far side of the flat. Two openings on different walls, or the air does not move at all; one window on its own is not cross ventilation.
2. Clear the coolest floor. Pull the rug off a patch of bare tile in the room with the fewest external walls, which in a block of flats is usually a middle unit with neighbours on both sides.
3. Wet the animal's undersides, belly, groin, armpits and paw pads, with a cloth and water cooler than the animal, and wet them again as the water evaporates.
4. Refill the bowls and drop ice into one of them, which both the RSPCA and the Royal Veterinary College endorse.
5. Strip the bed. Take the blanket, the cushion and any spent cooling mat out of the crate, because a warmed mat and a folded blanket are both insulation at that point.
6. Then sit down and watch the animal, because with no thermometer on the wall the animal is the only instrument you have.

Four things people do during a cut, and what is wrong with each

Four common responses to a hot flat make the animal worse or do nothing, and each has a named welfare or veterinary body behind the correction. They are the wet towel over the body, the spent cooling mat, the closed bathroom, and the belief that ice is dangerous.

One: the wet towel laid over the back

Do not put a damp towel over an animal's body. The RSPCA's wording is unambiguous: placing damp towels directly over your dog's body can trap heat and worsen their condition, there may be some value in placing wet or damp towels under your dog but never over their body, and the towel must be re-wetted frequently to improve the cooling effectiveness. The reason is the mechanism in the previous section. A soaked cloth lying on fur stops air reaching the skin and becomes an insulating layer the moment it warms to the animal. The same cloth under the animal, re-wetted, is conducting heat away. The correction is a change of position, not a change of equipment.

Two: the cooling mat with nowhere to put its heat

A cooling mat is a heat sink with a fixed capacity, and once it is full it stops being a cooling mat. The RSPCA's dog welfare expert puts it exactly: monitor the mat regularly during use, because some can retain heat once they have warmed up or reached the end of their cooling effect, potentially making your dog hotter rather than cooler. In an ordinary summer afternoon the mat gives its heat back to a room that is cooler than it is. In a flat with no power, in the hours either side of that 8 to 9 pm indoor peak, there is nowhere for that heat to go, so the mat saturates faster and stays saturated. What the products are and what the gel inside them is are covered in cooling vests and summer gear in India.

Three: shutting the animal in the bathroom

Leave the bathroom door open rather than shutting the animal inside it. The instinct is sound, because the bathroom usually holds the coolest tile in the flat and cats find it on their own, gravitating to tiles and porcelain when they are a little too hot. The error is the door. The Royal Veterinary College names a warm or humid environment that is poorly ventilated as a cause of animals quickly overheating, and International Cat Care warns specifically about a cat confined to a room that gets very hot International Cat Care. An Indian bathroom is small, usually has one high window or none, and in most flats is ventilated by an exhaust fan that is off during a cut. What it has as a room is the opposite of what it has as a surface. The surface is worth having and the sealed box is not, so the rule is the floor without the door.

Four: thinking ice is dangerous

Ice in the drinking water is safe and the belief that it is not is a myth two bodies have now corrected. The RSPCA lists it under exactly that heading: offering ice cubes or frozen treats for your dog to eat in hot weather can be safe when done correctly, and crunching or licking small amounts, or popping them into the water bowl, can help cool your dog down, with supervision against choking. The Royal Veterinary College's prevention list says the same from the other direction: ensure your pet always has drinking water available, adding ice can help keep it cool. In a flat where the overhead tank has been in the sun all day, that matters more than it sounds.

What to keep in the flat before the power goes

Keep five things ready before a cut, and four of them are already in the house. The deliverable here is not a shopping list, because the interventions with the best evidence behind them cost nothing; it is deciding where they live so that you are not opening cupboards in a dark 36 C flat.

1. Water drawn in the early morning and kept out of the sun. An overhead tank is a tank in the sun, and water drawn from it at 3 pm comes out warm. The bowl, the biofilm and how much an animal actually drinks are on summer hydration for pets in India; what belongs here is the volume. Fill more than you think, before you need it.
2. Two cloths and a jug, kept together, in the room the animal uses. This is the intervention the Royal Veterinary College describes and the only one that works with no electricity at all.
3. Two or three filled bottles standing in the freezer, year round. Wrapped in a cloth they are the heat sink both the RSPCA and International Cat Care suggest, and a full freezer holds its cold far longer than an empty one.
4. A torch or a battery lamp, so nobody opens the fridge for light. Every door opening during a cut spends cold you will want for the bottles.
5. Two phone numbers, saved before summer: a neighbour with a working inverter, and the nearest clinic that is open late. The Animal Welfare Board of India asks for immediate veterinary attention at any sign of heat distress, and a number you have to look up at 9 pm is a number you do not have.

Note what is not on that list. No product appears, because nothing sold for cooling an animal outperforms a cloth and a jug once the electricity is off, and because the one piece of equipment that is genuinely worth money is the thing the next section is about. The rupee cost of being ready for a cut, in a house that already owns a jug and a towel, is zero.

The inverter question: what it will realistically run

A household inverter runs the ceiling fan, and for an animal the ceiling fan is the only load on it that matters. An ordinary Indian induction-motor fan consumes about 75 W at top speed, and the minimum now mandated for the labelled range is 53 W, which is a small enough load that the arithmetic comes out in your favour.

Those are the right numbers to start from because the fan is close to universal here. About 88 percent of Indian households own a ceiling fan, there are roughly 40 to 50 crore of them in the country, and they account for about 40 percent of residential electricity consumption. Most five-star models now sold use brushless direct current motors, which is why a new fan draws so much less than the one it replaced. An unrated 75 W induction fan still sells for about Rs 1,500, while labelled models run from roughly ₹2,500 for a one-star to an average of ₹7,600 for a five-star.

Nobody publishes a table of how long a given Indian inverter will run a given fan, so here is the arithmetic instead, with its assumptions stated so you can redo it on the numbers printed on your own unit. Usable energy equals battery voltage multiplied by amp-hours, multiplied by the fraction of the battery you are willing to discharge, multiplied by the inverter's conversion efficiency. Run time equals that figure divided by the total watts you are drawing.

Read the last two rows against the survey finding that unscheduled urban outages last up to 12 hours. Two fans on a single ordinary battery cover a typical evening cut and do not cover the worst one, and every light, router and television you leave on that circuit eats into it. The decision that follows is unglamorous and specific: during a long cut, run one fan in the room the animal is in and switch the rest of the house off.

Cats are a different animal in the same room, and one number explains it

A cat is comfortable at temperatures that distress a dog, and the figure behind that is the thermoneutral zone. The National Research Council puts the feline thermoneutral zone at 30 to 38 C, against 20 to 30 C for dogs and 18 to 25 C for humans.

Hold that against the Chennai measurement and the consequence is immediate. A flat sitting between 31 C and 34.7 C for most of the 24 hours is inside a cat's thermoneutral zone and above the top of a dog's. The same room, at the same hour, is two different rooms depending on which animal is lying in it. The dog in that flat is working to shed heat. The cat beside it may be perfectly comfortable, and will show you nothing.

That is the real problem with cats during a cut, and it is the reverse of the one people expect. The cat is not giving you an early warning, because for a long stretch of the curve there is nothing to warn about. Cats are also, as International Cat Care puts it, generally good at taking care of themselves, finding the coolest spot on their own and gravitating to tiles and porcelain when they are too hot. Right up until the spot they choose is one they cannot get out of.

The hiding places, and the Indian versions of them

International Cat Care's warning is about outbuildings: always check sheds, greenhouses and summerhouses before closing them up, because cats can find their way inside seeking a shady spot and trapping them inside can lead to heatstroke and dehydration, and check the car before you lock it for the night. An Indian flat has no shed and the same hazard. The equivalents are the store room off the kitchen, the loft above the bathroom, the space behind the fridge, the washing machine with the door left ajar, the inverter cupboard and the stairwell meter room. A cat shut in any of those during an evening cut is in a space with no ventilation inside a building that is handing back its heat.

• Count the cats before you close any door, including the one you are leaving the flat by.
• Check the washing machine and the loft hatch specifically, because both are closed without looking.
• Treat the inverter cupboard as a hot place, not a cool one. A battery and an inverter under load generate heat, and this is an inference from how the equipment works rather than a measured figure.
• Tap the bonnet and look in the wheel arch before starting a car in the compound, which is International Cat Care's rule and holds in summer as well as winter.
• Leave the coolest room accessible all day, with the door wedged rather than latched, so a cat that wants the bathroom tile does not need you to open it.

What heat stress actually looks like in a cat, which is quieter and later than in a dog, and the 40 C body-temperature line, are set out in heat safety for cats in India. The one sign worth repeating here because it changes what you do in the next five minutes: a cat breathing with its mouth open at rest is not cooling itself the way a dog is. It is in trouble.

The animals with no margin at all

Six groups of animal reach the failure point sooner than a healthy adult, and the Royal Veterinary College names them: animals that are overweight, flat-faced breeds such as Pugs and French Bulldogs or Persian cats, pets with thick coats, old or very young animals, and animals with pre-existing conditions, particularly airway, lung or heart problems.

For every one of those, the plan in this page is not enough on its own, because the margin that lets a healthy animal ride out a three-hour cut is the margin they do not have. A brachycephalic dog or cat is short of airway before the heat starts, and what that costs it, with the Indian context and the grading, is on brachycephalic obstructive airway syndrome. A senior dog or cat may simply not move to the cooler room, which is covered on senior dog care in India and senior cat care in India. For these animals a long cut is a reason to leave early rather than a reason to try harder.

The temperature at which there is no home remedy, and nobody has measured it

At some indoor temperature there is no home remedy and the only answer is to leave, and no study has established where that line sits for a dog or a cat in an Indian home. This section sets out what has been measured, in humans, and what follows from it.

The nearest measurement is from human physiology. A wet-bulb temperature of 35 C has long been theorised as the limit of human adaptability to heat, and when that threshold was finally tested on people rather than argued from principle, it did not hold. Across six experimentally determined environmental limits, no subject's critical wet-bulb temperature reached 35 C and every mean was significantly lower; in humid environments the mean was 30.55 plus or minus 0.98 C. Those were young, healthy adults performing tasks at modest metabolic rates mimicking basic activities of daily life.

Now set the two measurements side by side without doing arithmetic across them. The Chennai homes sat above 34 C for hours after sunset with relative humidity above 75 percent, and the measured limit for a young healthy human in humid air is a wet-bulb temperature around 30.5 C Vecellio DJ, Wolf ST, Cottle RM. Hot, humid Indian indoor air is not a comfortable distance from the limit of the species that has actually been tested. For a dog, which cools by panting rather than by sweating over its whole skin, and for a cat, which has almost no evaporative surface beyond its paw pads and its tongue, the equivalent experiment has never been run. Anyone who gives you an indoor temperature at which a dog is no longer safe in an Indian flat is giving you a judgement.

The decision rule, stated as a rule and not as a number

To decide when to leave, watch the animal and the direction of travel rather than a thermometer reading. Leave when any one of three things is true: the animal is panting at rest and the room is not getting cooler after you have wet it and opened what can be opened; the cut has run long enough that everything you can wet is wet and the frozen bottles have gone soft; or the animal is in one of the groups with no margin and the cut is forecast to be a long one. Those three are a judgement, offered as one. The only Indian page that puts a number on it suggests moving a cat if a cut passes two hours with the flat above 38 C, and that page gives no source for the figure.

Where to go is the part to settle in advance, because India has no pet-inclusive answer waiting. Stone and colleagues found that the designated public cooling centres in their three study cities would accommodate no more than 1 to 2 percent of the urban population during a concurrent heat wave and blackout, and that none of the three cities' plans required back-up power to keep those centres cooling. India's version of that gap is wider still. In practice the options are a neighbour or relative with a working inverter or a running air conditioner, a veterinary clinic that will hold the animal in a cool room, or a shopping centre that will let a carrier in. The same preparation logic applied to a different emergency is set out on a pet evacuation plan for an Indian flood.