Complex sentence: In districts that were impacted most, the heat was so severe that ponds and rivers evaporated and in the same districts, birds had fallen from the sky and animals were collapsing from the intense heat.
Split into simpler sentences: In districts that were impacted most, the heat was so severe that ponds and rivers evaporated. Moreover, in those districts, birds had fallen from the sky and animals were collapsing from the intense heat.