THERMAL TRAP: How to protect yourself from El Niño’s extreme heat

El Niño is here, and its impact will touch every part of our lives.

If you’ve paid attention to the news lately, you’ve probably seen relentless headlines detailing the threats of the super El Niño sweeping across South Africa.

Warnings abound that El Niño will plunder our water resources, strain our food supply and compromise our health.

“More than anything right now, I think we need calm. We’ve had El Niños before, and we will be able to survive this one,” said Professor Sibusiso Mkwananzi, a senior researcher and demographer at the Wits Reproductive Health and HIV Institute (Wits RHI).

Wits RHI is a leading global and regional authority at the intersection of climate change, extreme heat and public health, focusing on protecting vulnerable groups, particularly pregnant women, infants and healthcare workers, and transforming health systems to withstand rising temperatures.

El Niño is far from rare – it is a natural climate pattern in which a massive pool of warm water forms in the Pacific Ocean and releases heat into the atmosphere, raising global temperatures.

What is rare, however, is a super El Niño, which is an extra-strong version of the natural phenomenon supercharged by human-induced global heating, causing extreme heat.

As temperatures surge, the nation sits at a threshold where rising temperatures are no longer just a weather story but a threat to public health, human equity and medical resilience.

How extreme heat affects health

Mkwananzi said that extreme heat can cause heat exhaustion (fainting, headaches, thirst, fatigue), which can escalate to heat stroke.

She further explained how the body attempts to thermoregulate (the biological process that keeps your internal core body temperature stable) through sweating, but when temperatures become too high, thermoregulation becomes difficult.

"There comes a certain temperature where thermoregulation is no longer possible because you’re not able to sweat any more. Also, because the temperature is so high, the proteins and other vital hormones in your body end up denaturing (breaking down), and the body starts shutting down. When that happens, that’s now termed heat stroke. That’s a medical emergency,” said Mkwananzi.

While heat stroke can affect everybody, Mkwananzi added that the most vulnerable are children, who are more susceptible due to immature thermoregulatory systems and an inability to prioritise self-protection (drinking water or staying in the shade), and pregnant women and women who have just given birth, those with chronic illnesses and the elderly.

Over and above this, structural inequalities also exacerbate the effects of extreme heat on health. When heatwaves hit, they often turn informal settlements and rural townships into thermal traps.

“But the research that we have conducted in informal settlements has found that, actually, in informal housing in homes that are made of corrugated iron, the temperatures can be anything from three to five degrees Celsius higher inside than outside,” said Mkwananzi.

For community members managing chronic conditions such as HIV, active tuberculosis, hypertension or cardiovascular disease, prolonged exposure to these temperatures can trigger severe cardiovascular stress, electrolyte imbalance and acute kidney impairment. Furthermore, outdoor labourers, agricultural workers and elderly residents living without mechanical cooling bear a disproportionate burden of acute heat exhaustion and heat stroke.

A study from the Climate Impact Lab warned that the super El Niño could cause approximately 1,200 additional heat-related deaths in South Africa from September 2026 to February 2027. Globally, it is projected to claim more than 450,000 lives.

However, sensational reporting on projected deaths without detailing preventative measures is counterproductive. Mkwananzi believes the focus should be on empowering the public with strategies to protect themselves.

“We need such data to know what is coming, but the problem is that people don’t mind being told about a danger that is coming. But what people want, when they are being told about a danger, is to also be told how to avoid the danger,” said Mkwananzi.

How can people cope?

While systemic infrastructure overhauls require long-term capital investment, immediate, low-cost community-level interventions offer practical protection against extreme heat. These include:

• Reflective roof coatings: Painting dark corrugated metal roofs with reflective solar-white paint can reduce indoor surface temperatures by 8-12°C, significantly reducing radiant heat indoors.

• Community greenery and shade canopies: Planting fast-growing indigenous shade trees and erecting simple shade awnings over public assembly areas, clinic queue lines and school yards to disrupt local urban heat island effects.

• Hydration depots and early warnings: Establishing neighbourhood-level water distribution points paired with SMS-based early warning alerts advising residents on heat safety, work-rest cycles and hydration schedules.

• Passive cooling knowledge: Training community health workers to teach families passive cooling methods – such as strategic cross-ventilation and applying damp cloths to the backs of the necks of infants and elderly individuals.

Mkwananzi said Wits RHI had successfully conducted several projects providing vulnerable communities with low-cost cooling strategies.

She said they provided women with either an “umbrella hat”, water bottle and battery-operated handheld fan, or a desk fan with water misting function powered by a solar panel.

Mkwananzi added that Wits RHI also co-developed and tested an app that provided daily heat-related guidance based on temperature, aiming to increase knowledge and promote protective behaviours.

Preparedness of the healthcare system

According to Mkwananzi, South Africa’s public healthcare system is largely unequipped for climate-driven health crises because traditional medical curricula have rarely incorporated climate change epidemiology.

“Our training as health scientists in general has never included climate change... If you don’t explain to a healthcare worker how climate change is causing complications in a pregnant woman, they’re going to say that it’s hullabaloo,” said Mkwananzi.

To bridge this gap, Wits RHI has piloted rapid, one-hour training modules for clinic staff. These sessions guide workers through the exact physiological mechanisms of heat strain, targeted patient counselling (such as trimester-specific pregnancy advice), and practical facility-level adjustments, like maintaining window ventilation, ensuring working maintenance logs, installing water dispensers and erecting JoJo storage tanks.

Health as a key focus in climate policy

For years, climate adaptation and mitigation policies in South Africa have focused on the energy transition and carbon emissions, leaving public health as a downstream secondary concern. However, health is one of the human faces of the climate crisis, and the number of deaths projected as a result of the super El Niño requires the nation’s climate leaders to include the effect that rising temperatures will have on the population in the conversation.

"Let us rather focus on climate adaptation because we are the most vulnerable to climate change. We don’t cause the problem, but we are affected by the problem so much. Government needs to start thinking about how we make the spaces people live in cooler,” said Mkwananzi. DM