I think it is become the vehicle moves so fast. Anything over 15mph has the effect of shredding the etheric layer. Cold water holds and sequesters malefic etheric energy and restores protective energy to the body. The same is true of sunlight, which is why sunbathing is restorative and so are hoodoo baths. Being in a car, plane, or train tends to do the opposite. It amplifies malefic energy and makes it stickier/congested and strips the beneficial layer away.