Complex sentence: On descent, the weather worsened quickly, and Božić's team was unable to return to base four before dark, so they were forced to spend the night in the open, without tents or sleeping bags, at an altitude of.
Split into simpler sentences: On descent, the weather worsened quickly, and Božić's team was unable to return to base four before dark. They were forced to spend the night in a temperature, without tents or sleeping bags, at an altitude of.