Surprisingly, almost no one experiences motion sickness in a hot air balloon, even those who are prone to it in cars, boats, or planes. This is because a balloon moves at the exact same speed as the wind, meaning there is no "relative motion" or wind-rush against the basket. Motion sickness is caused by a sensory conflict where your inner ear feels movement that your eyes cannot match; in a balloon, the basket stays perfectly steady, and the ascent is so gentle it feels like the "ground is dropping away" rather than the basket moving up. There is no swaying, rocking, or vibration from an engine. Furthermore, because you are in the fresh, open air, you avoid the claustrophobic or "stuffy" triggers of a plane cabin. The only time you might feel a slight "bump" is during the landing, but the flight itself is described by most as the smoothest form of travel on Earth. If you have a severe fear of heights, you might feel some initial anxiety, but the lack of physical motion usually prevents any actual queasiness.