In May, temperatures soared above 52° Celsius (125.6° Fahrenheit) in Pakistan’s southern province of Sindh. To cope, Samina Kanwal, a community health worker with Action Against Hunger, began work at 7:00 am — the earliest time possible given neighborhood security protocols — to travel door-to-door helping vulnerable with the health consequences of extreme heat including heatstroke, difficulties with brain function, and even hunger.
Of course, these consequences extend beyond Pakistan with the world experiencing the hottest day ever recorded this summer. The health implications are real — and they are growing with the heat.
Heat is a Health Risk
Over time, heat strains the body as it tries to cool itself, worsening chronic conditions from asthma to diabetes. It is also causes pregnancy and birth complications, with the rates of premature births increasing after heat waves.
Heat-related illness occurs because of exposure to high temperatures. Heatstroke can develop in just a few hours and can involve seizures, heart complications, and brain swelling, with high fatality rates. In fact, heat-related deaths worldwide increased by 74% from 1980 to 2016, and researchers attribute nearly 40% of those deaths to climate change.
A drought and a heat wave hit the Baluchistan region of Pakistan in June 2024. Credit Action Against Hunger
Diarrhea – the third leading cause of death in children younger than five in average temperatures – is much more severe in extreme heat when the symptoms of severe dehydration and fluid loss are compounded. While people typically are advised to drink more fluids as temperatures rise, that assumes access to clean water, which isn’t the case for more than 2 billion people worldwide.
Brain health is impacted by extreme heat: cognitive function decreases as temperatures rise. One study found that for every degree above 22° Celsius (72° Fahrenheit), standardized test scores fell 0.2% — assuming that school takes place at all. In communities with limited resources, climate-controlled buildings are rare. To protect students, Pakistan’s Punjab province closed schools for a week this summer, leaving 52% of school-age children at home.
Mental health also suffers due to extreme heat. Hot days are associated with higher risk of emergency room visits for substance abuse, mood and anxiety disorders, schizophrenia, and dementia. Studies show that every 1° increase in temperature can increase suicide rates. The effects are pronounced in agricultural areas, where heat damages crops and economic prospects.
During May’s heatwave, the need for antibiotics and antipyretics (also known as fever reducers) became so great that Action Against Hunger, local authorities, and other partners quickly came together to prevent shortages and manage other health risks, like filling and carrying jugs of clean water. To reduce the impacts on the women and girls that this task typically falls to, we expanded shaded areas around community water sources.
Heat and Hunger
Drought and crop failure are obvious consequences of heat that impact food accessibility. High temperatures can dry soil, lowering crop yields and driving up food prices. These impacts become more widespread as climate change accelerates, and it’s already impacting nutrition among vulnerable populations.
Extreme heat intensified chronic and acute malnutrition in multiple West African countries, an area vulnerable to deadly heat waves. Over a 90 day period, just 14 days of temperatures between 86 and 95° led to a 2.2% increase in child “wasting,” which happens when a child loses muscle and fat tissue, becoming too thin for their height.
For every 100 hours of exposure to a temperature above 95° Fahrenheit, the “stunting rate” among children — where a child is too short for their age — increased by 5.9%.
Today, one in four children is undernourished. But researchers have warned that if the global temperature increases by 2°, the rate of stunting due to heat exposure will nearly double. Without a concerted effort from the global community to mitigate climate change, the world is on track to surpass this threshold, leading to devastating health impacts for children, families, and communities.
Low-income countries will feel these effects the most, as most poorer nations are located in regions that will be two to five times more susceptible to heat waves than richer countries by the 2060s. These challenges are compounded by other climate impacts: Pakistan, one of the countries most impacted by climate change, suffered drought followed by historic flooding that submerged crops and killed thousands of livestock that people rely on for basic food and income.
This zig-zag between extremes has left more than two million people in need of emergency assistance. The climate crisis is a health crisis. Paradoxically, heatmakes it harder to engage in protective measures. And health systems are not well prepared to deal with an additional influx of patients alongside the burden that heat waves place on everything from supply chains to the power grid.
Solutions for the Future
The good news is that efforts are underway to create more climate-resilient health systems. Leaders increasingly recognize the need for a “one health” approach that acts on the interconnections between human and environmental health. We also need to ensure that the links between heat and hunger are central to that agenda.
Developing climate change early action plans and leading simulation exercises for key stakeholders is crucial to a solution. We have implemented programs, for example, that contributed to agricultural benefits over time: farmers were able to store 15% additional seeds for the next cultivation cycle, and preservation practices of rice and wheat stock improved by 100%.
Beneficiaries also reported a 25% decrease in soil-related issues due to flooding, which shows that the program had a positive impact on mitigating the effects of climate disasters. The introduction of irrigation systems and water management techniques helped farmers overcome weather-related challenges.
Solutions like income generation opportunities, promotion of climate-smart agriculture practices, climate-friendly irrigation systems, provision of treatment for severely malnourished children, and additive health services will be key to creating a sustainable and thriving world amid increasing temperatures.
Muhammad Aamir is Pakistan Country Director, Action Against Hunger
