The nation of Mozambique begins three days of mourning Wednesday following the catastrophic strike of Cyclone Idai, even as the waters continue to rise and a new threat emerges: extreme heat.

And more rain.

The Instituto Nacional de Meteorología issued an alert warning that temperatures of 38C to 41C (100 to 106 degrees) are expected in Inhambane and Gaza provinces, where deadly floods already have impacted their northern portions. The intense heat warning also is issued for Maputo to the south.

Meteorologists issued a heavy rain warning for the rest of the week. In the hard-hit provinces of Manica, Zambezia and Sofala – where a crippled and broken Beira is the capital – rain rates of 75mm per day with severe storms are forecast. Moderate rain rates up to 50 mm per day are expected for Inhambane and Gaza.

It’s hard to imagine yet another challenge for Mozambicans, who are experiencing what Clare Nullis, spokesperson for the World Meteorological Organization (WMO), says may be the greatest disaster ever caused by cyclone in the Southern Hemisphere.

The World Food Program said Mozambique’s crisis is “a major humanitarian emergency that is getting bigger by the hour.”

The death toll in Mozambique stands at 202 but is expected to rise, according to the UN Office for the Coordination of Humanitarian Affairs. That’s in a region with more than 2.6 million people affected, some perched on roofs or in trees, cut off by extreme flooding and without food, water or medical care. Buzi, home to 200,000 people, is at risk of being submerged as flood waters may rise to eight meters.

“The next 72 hours are expected to be critical, with water expected to rise above alert levels in the Buzi and Pungoe river basins and a continued high risk of urban floods in Beira and Dondo,” said UNOCHA. “Meanwhile, thousands of people in Zambezia and Tete remain in need of assistance following floods that began in early March.”