Much of South Africa has been hit by a heatwave which is expected to continue until Saturday in North West, Free State and Northern Cape, the South African Weather Services (Saws) said on Wednesday. 

“However, it should be noted that although some places do not meet the technical definition of a heatwave, they are also expected to experience extreme heat, and the public in those areas are advised to also take the necessary precautions,” Saws said. 

These precautions include hydrating, avoiding outdoor activities during the hottest time of the day, wearing appropriate clothing and ensuring that vulnerable individuals are cared for. 

Added intensity

Increased heatwaves in SA align with global average temperatures that have recently been found to have increased by 1.7°C compared with pre-industrial levels, the journal Nature recently reported. The year 2023 was reported to be the hottest on record with parts of the globe experiencing extremely high temperatures and wildfires.

There have been raging wildfires in the Western Cape, with 6,000 reported between December 2023 and January 2024, burning nearly 100,000 hectares of land. The fires have been exacerbated by the El Niño weather phenomenon and dry, windy conditions.

Read more in Daily Maverick: Taking stock — staggering scale of Western Cape wildfires as fire season continues to rage

Dr Dawn Mahlobo, the senior manager of climate services at Saws, told Daily Maverick that heatwaves during this time were normal, but that in the past, temperatures had not been this intense. 

“Now there is also the effect of El Niño, bringing on warmer than normal temperatures, thus intensifying the heat,” Mahlobo said.

“This heatwave has been very intense because we have even broken some records … because of climate change, we are seeing a lot of changes in our weather patterns, especially over the eastern parts of South Africa; they become more intense, leading to very high temperatures.” 

Mahlobo said that parts of South Africa are in a subtropical region where climate change is shifting weather systems such as the Hadley cell, causing less rainfall and drier conditions in the northwestern and eastern parts of the country.

The Department of Health’s National Health Action Guidelines state that extreme heat can cause dehydration, heat cramps, heat exhaustion and heat strokes that can manifest as damage to the brain, kidneys and other organs. 

“The majority of deaths and other health conditions during extreme heat are, however, not from heat stroke, but from exacerbations of chronic medical conditions or in frail, elderly people. Extreme heat can also affect mental health, including worsening of anxiety, irritability, interpersonal violence and gender-based violence,” the document reads. 

Read more in Daily Maverick: Climbing temperatures pose risk to health and strain healthcare systems — expert

In addition to the announcement of the heatwave, Saws issued an alert that there were conditions for severe thunderstorms, which could result in flooding of roads and settlements, damage to property and infrastructure, power surges and injuries from lightning.

Preventive measures

Dr Nicholas Brink, a research consultant at the Wits RHI Research Institute, told Daily Maverick that populations vulnerable to the impact of the heatwave included children, pregnant women, the elderly and people who cannot shelter from the heat, including those living in informal settlements where access to shade and water is an issue. 

“Heatwaves have an unequal effect on society, and that is a big concern. Heatwaves have both direct and indirect effects, with the most serious direct complications being heat stroke, where the body is no longer able to regulate its temperature effectively,” said Brink.  

“There’s a need to look out for vulnerable populations … and ensure you can help them out; going to run an errand for them [during a heatwave] for example. This extends to occupational areas as well… Employers should ensure there’s water for construction workers, encouraging hydration, and allowing more rest time. Research even shows that it can improve productivity and lessen complications from the heat.” DM