MIAMI — With sheet metal roofs, concrete floors, poor ventilation, and spotty electricity, crowded urban slums in Africa can expect to get even hotter and deadlier due to global warming, US researchers said Monday.

Scientists at Johns Hopkins University analyzed three informal settlements in Nairobi, including the largest, Kibera, home to nearly a million people.

Along the settlements鈥 narrow alleyways, mud-walled homes and metal roofs, they found stifling temperatures, 鈥渂etween five and nearly 10掳 Fahrenheit (2.7掳-5.5掳C) higher than those reported at Nairobi鈥檚 official weather station less than half a mile away,鈥 said the study in the journal PLOS ONE.

The study was conducted by 11 researchers over the course of 80 days from late 2015 to early 2016, one of Nairobi鈥檚 hottest summers since the 1970s.

Researchers posted 50 thermometers on trees and wooden posts, most in shaded areas.

At the Kenya Meteorological Department headquarters, in a grassy, wooded area, average daytime temperature was 78掳 Fahrenheit (25掳C).

In the slums, the average was nearly 82掳 (27.7掳C) in Kibera, 85掳 (29.4掳C) in Mathare, and 87掳 (30.5掳C) in Mukuru.

The higher temperatures found in the study are 鈥渃ertainly consistent with excess deaths,鈥 said lead author Anna Scott, a climate scientist in the Department of Earth and Planetary Sciences at Johns Hopkins.

However, researchers were unable to quantify how many people are likely to die from heat waves in these urban areas, since many variables are at play.

Up to 60% of Nairobi鈥檚 residents live in these informal settlements. — AFP