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When the daytime air feels like an oven and night brings no relief, people in Karachi, Pakistan, say the heat “goes straight to the head”. They mean more than dizziness or sweat.

It’s the creeping panic of a body that cannot cool down: restless nights, frayed tempers, a household on edge. Here, a heatwave is not simply a matter of high temperatures. It’s a public health emergency that seeps into every corner of life: physical health, sleep, mood and the invisible care work that keeps families and neighbours alive.

Our research in Pakistan and Kenya (Karachi, Lahore and Nairobi), shows how extreme heat affects local communities.

For families living on informal and unstable incomes and in fragile housing, such heat is not just uncomfortable; it can be deadly.

Heatwaves occur when temperatures push daily highs past 40 °C inland and above 35 °C on the coast. In 2015, a single heatwave killed more than 1,200 people in Karachi during just one week in June. But the quieter psychological toll which is rarely counted in official statistics builds with every wave of extreme heat.

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In our research, residents describe lying awake in stagnant air, waking drenched in sweat and starting the next day already exhausted. Sleeplessness makes emotions harder to manage, fuelling conflict in homes stretched thin. Many, especially women, speak of a sense of suffocation and dread; fearing their bodies won’t cope or that a loved one will collapse. For people with asthma or anxiety the symptoms are magnified, and mothers often feel an acute worry for children and elderly relatives.

This mental strain is no overreaction, it reflects harsh realities. Outdoor workers lose wages when extreme heat makes it unsafe to stay on the job. At the same time, food and water prices climb as supply chains falter and demand spikes, just as family incomes shrink. Hospitals and clinics can be difficult to reach because high temperatures often lead to power cuts, overloaded transport systems and an increase in heat-related illness, all of which slows emergency care.

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Women often shoulder the heaviest burden because in many households, especially in low- and middle-income countries, domestic and caregiving duties still fall largely to them. Social norms often expect women, not men, to stay home with children, care for older relatives and organise water or food supplies. When a heatwave strikes, those tasks become more physically demanding and more time-consuming: fanning overheated children through sleepless nights, checking constantly on elderly neighbours, and answering calls for help.

In low- and middle-income countries, women also face disproportionate health risks from climate change, particularly during extreme heat, precisely because these gendered roles and socio-cultural expectations expose them to greater stress. The unpaid labour that holds households together – caring, fetching water, preparing food – is carried mainly by women. As one Karachi resident explained, on the hottest days she and her neighbours watch over pregnant women:

Women here may be poor, but they support each other, sharing water, looking after each other’s children and cooking for each other. It’s our way of surviving…

Such neighbourly care surfaces again and again. Families pool money to buy safe drinking water when supplies run short. In some informal settlements, one of the most immediate ways people cope with rising heat is by increasing their reliance on water, often through hand pumps that serve as vital lifelines during prolonged heatwaves. Neighbours check on older people during power cuts. Women take turns cooking when kitchens become unbearable for elderly or pregnant relatives. These are not feel-good tales of “bouncing back,” but acts of collective survival: immediate, exhausting and often invisible. They reveal how vulnerability is shaped by poor housing, patchy healthcare and weak governance – factors that leave people exposed when crises strike.

Extreme heat also compounds heat related health risks and financial costs. In crowded settlements and displacement camps, food spoils quickly, appetites wane and clean water becomes harder to find and more expensive to acquire. Pregnant and breastfeeding women struggle to maintain nutrition. International research shows that heat stress can deplete micronutrients, hinder growth and increase the risk of early labour and premature childbirths. When these pressures collide with poverty and displacement, the dangers of malnutrition and long-term harm can only grow.

Residents’ requests are strikingly simple. They want electricity that stays on through the night, clean water that they can afford and clinics that remain open when symptoms worsen. These are not luxuries. They are the difference between anxiety and peace of mind, between starting the day rested or already exhausted.

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Even small interventions help: a working fan, a shaded community space, advice on hydration and sleep. Women-led groups already organise water-sharing, neighbour check-ins and shaded play areas. Strengthening these networks, and centring polices on women’s health could save lives and protect mental health during future heatwaves.

Counting only hospital admissions or heat-stroke cases misses what people say matters most: a child kept hydrated, a safe place to sleep, the absence of panic on the hottest days and nights of the year. These everyday markers of dignity and survival are where real adaptation begins. As one resident put it: “We cannot stop the sun. But we can stop each other from being alone in the heat.”

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Gulnaz Anjum, University of Limerick and Mudassar Aziz, University of Oslo

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Gulnaz Anjum is an Assistant Professor at the Department of Psychology, University of Limerick.

Mudassar Aziz does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.