Complex sentence: Another important aspect of high altitude flight involved physiological problems that balloonists would experience when exposed to conditions at great heights, and Berson assisted physiologists Hermann von Schrötter and Nathan Zuntz with pioneer experiments in aviation medicine.
Split into simpler sentences: Another important aspect of high altitude flight involved physiological problems that balloonists could experience when exposed to conditions at great heights. Here, Berson assisted physiologists Hermann von Schrötter and Nathan Zuntz with pioneer experiments in aviation medicine.