From RollerCoaster Tycoon Wiki Wiki, the RollerCoaster Tycoon encyclopedia that anyone can edit.

How do you cure nausea? Is is possible to cure it after ride patrons exit, or should I just try to create a ride with less nausea? 05:41, January 4, 2012 (UTC)

Benches First Aid Room, and Toilets near the exit help, but people can still get sick.
Mixing your rides can help or not. Thrill-seeking guests will simply ignore gentle rides placed between two coasters and even if you mix more (wooden) and less (steel) nauseating coasters, your guests can simply decide to ride the more nauseating coaster over and over, until they finally vomit.
The best tip is to avoid placing food stalls near your most nauseating coasters, also placing benches next to the food stalls is important, this way your guests don't wander around eating and then enter a more nauseating ride directly afterwards.
Everything else you have to take care of with handymen. Sucinum 08:08, January 4, 2012 (UTC)