Johannesburg - The South African Weather Services on Tuesday warned residents of extremely hot conditions expected over the Cape Winelands, Central Karoo and the interior of the Garden Route in the Western Cape, as well as a heatwave over the eastern parts of the country, Northern Cape, Free State and North West provinces.

The Gauteng Weather Service said the province had started experiencing extremely high temperatures from Monday, expected to last until Saturday, with temperatures seen reaching over 36 degrees Celsius. It urged people to stay indoors under cool temperatures or near fans if possible.

"The old and infirm must take extra care to stay hydrated and cool. Avoid strenuous outdoor activity, playing excessive sport and hard labour," the service said. "Dress in light-weight clothes and drink plenty of liquids NOT alcohol. Ensure pets and livestock have enough access to water."

With temperatures on Tuesday expected to reach 41 degrees Celsius in Upington, 40 degrees in Beaufort West and Graaff-Reniet, 39 degrees in Rustenburg and 35 degrees in Pretoria, scores of people took to social media to express their frustration over the extreme heat and share tips on how to stay hydrated.

On Monday, the City of Johannesburg's Emergency Management Services also warned residents to take precautions.