Doctors will not perform surgeries when the Foehn is blowing because it is known that patients do not heal as well or as quickly. The Foehn winds are said to flush an increase of positive ions into an area. It has long been known in the Zen religion that the best places to meditate were by a crashing ocean, in a cave, or by a waterfall, and the best place was in a cave behind a waterfall. It has been found in modern times that all of these places have excess negative ions. The worst places to be are in closed, poorly ventilated areas, especially with a lot of metal or computers in the room.
Airplanes are notorious for having high levels of positive ions.