How rising heatwave could become a top killer in Nigeria

Climate change rarely announces itself in ways that are easy to track. It is often framed through dramatic events, floods swallowing communities, droughts crippling farms, storms tearing through coastlines. But for Nigeria, the more defining impact may come in a quieter, less visible form: heat.

Not extreme heat as a one-off, but a steady, compounding rise in temperatures that gradually pushes up mortality.

This is the central warning from a new report by the Climate Impact Lab, which examines how rising temperatures will shape global death rates by mid-century. According to the report, by 2050, climate change is projected to increase temperature-related deaths in Nigeria by about 8 per 100,000 people.

On its own, that number might not trigger an alarm. Compared to countries like Niger or Burkina Faso, where projected increases exceed 60 deaths per 100,000, it can even seem modest.

But that would be a misread of the moment.

Because in Nigeria, the story is not about extremes. It is about accumulation.

When heat becomes a health issue
The science is straightforward. As temperatures rise, the human body works harder to regulate itself. Prolonged exposure increases the risk of cardiovascular stress, respiratory complications, and overall mortality. Unlike infectious diseases, which can spike and recede, heat operates differently, it raises the baseline.

In practical terms, it means more people die than would have otherwise, especially among vulnerable groups: the elderly, those with pre-existing conditions, and millions of Nigerians who work outdoors every day.

From traders in open markets to construction workers and farmers, exposure is not occasional, but constant.

This is how climate change begins to blur into public health.

Nigeria’s position in the heat belt
Geography matters. According to the report, countries closer to the equator are more exposed to rising temperatures, and Nigeria sits firmly within this zone.

In cooler regions of the world, warming actually reduces deaths by cutting cold-related mortality. But in already warm countries, there is little such offset. Heat-related deaths rise sharply, while any gains from fewer cold days are negligible.

This imbalance is what defines much of West Africa.

Across the Sahel, stretching through Mali, Chad, and Mauritania, mortality increases are projected to be among the highest globally. Cities like Niamey and Ouagadougou are already on track to see dramatic spikes in heat-related deaths.

Nigeria may not top those rankings, but it shares many of the same structural pressures: rapid urbanisation, population growth, and limited adaptive capacity.

In other words, it sits just below the extreme. but well within the danger zone.

The inequality factor
If heat is the trigger, inequality is the multiplier.

The Climate Impact Lab report finds that low-income countries are projected to account for ten times more climate-related deaths than wealthier nations. The reason is not just higher exposure, but lower capacity to respond.

In high-income countries, adaptation happens almost automatically. Air conditioning is widespread, healthcare systems are stronger, and urban infrastructure is better designed to handle heat.

In Nigeria, those buffers are uneven.

Electricity remains unreliable. Cooling systems are a luxury for many households. Informal housing offers little protection against rising temperatures. And healthcare access, particularly in rural areas, is still limited.

This creates what researchers describe as an “adaptation gap”, the space between what is needed to stay safe and what people can realistically access.

That gap is where mortality rises.

Cities as the frontline
Nowhere will this pressure be felt more than in urban centres.

As Nigerian cities expand, they are becoming hotter. Concrete replaces vegetation, heat is trapped, and night-time temperatures remain high. The so-called “urban heat island” effect is no longer theoretical, it is already shaping daily life.

In cities like Lagos, Kano, and Port Harcourt, this translates into longer periods of heat stress, particularly for low-income residents living in dense, poorly ventilated areas.

Across West Africa, similar patterns are emerging. In Ghana, for instance, Accra is already seeing measurable increases in temperature-related mortality.

The risk is not just that cities will get hotter. It is that they will become environments where heat and inequality reinforce each other.

A growing public health burden
One of the more striking implications of the report is that climate-related mortality could become one of the leading causes of death in parts of low-income countries.

This does not mean it replaces existing health challenges. Rather, it adds to them.

Nigeria already contends with malaria, respiratory infections, and non-communicable diseases. Rising temperatures will compound these pressures, increasing the overall burden on individuals and the healthcare system.

And unlike many diseases, heat is difficult to diagnose as a cause. Its impact is often indirect, making it harder to track and even harder to prioritise.

The narrow window for action
There is, however, a pathway to mitigation: economic growth.

As incomes rise, so does the ability to adapt, through better housing, improved healthcare, and access to cooling technologies. The report notes that globally, income growth could significantly reduce climate-related mortality by mid-century.

For Nigeria, this presents both an opportunity and a risk.

If growth is inclusive and translates into improved living conditions, it could act as a buffer. But if it remains uneven, large segments of the population will remain exposed.

Which brings the conversation back to policy.

Heat is still a blind spot in Nigeria’s climate response. Flooding, energy, and agriculture dominate the agenda, but temperature-related health risks receive far less attention.

Yet the solutions are not abstract. They include:

• Heat action plans in cities
• Public awareness systems
• Urban design that reduces heat exposure
• Stronger healthcare preparedness

None of these are out of reach. But they require recognising heat for what it is, not just a weather condition, but a slow-moving threat to human life.

The real risk is not that the impact is invisible. It is that it remains underestimated for too long.