Final answer:
When introducing hospital equipment to a frightened preschooler, nurses should use play therapy and simple explanations to alleviate fear, as this approach is age-appropriate and helps in making the equipment seem less threatening.
Step-by-step explanation:
The principle that nurses should follow when introducing hospital equipment to a preschooler who is afraid is to use play therapy and simple explanations to alleviate fear. This approach takes into account that children at the preschool age are in a developmental stage where they can be very imaginative and are learning to understand the world around them. Introducing medical equipment through play can make the equipment seem less threatening, turning a potentially scary situation into one that is more manageable for the child. Providing simple explanations that are age-appropriate helps in reinforcing understanding and reducing fear, fostering a sense of familiarity and safety.