What is a recommended treatment for air sickness?

Providing open air vents onto the passenger is a recommended treatment for air sickness because it helps increase airflow and can alleviate symptoms of nausea and discomfort. Fresh air can help settle an upset stomach and reduce the feeling of queasiness that often accompanies motion sickness.

Introducing cool air can soothe the passenger’s senses and distract them from their symptoms, making it a practical and immediate solution in an inflight scenario where passengers may experience air sickness.

While the other options might seem reasonable at first, they do not effectively address the specific symptoms associated with air sickness. For instance, providing solid food could exacerbate nausea rather than improve it, and applying heat to the abdomen is generally not associated with relief from motion sickness. Similarly, restricting fluid intake is not advisable, as staying hydrated can be important, especially in a flying environment.