In response to Mr. Duncan complaining of nausea, what should the nurse do first?

In situations where a patient presents with nausea, the priority is to establish a safe and clean environment. Washing hands and putting on gloves is a crucial first step as it ensures the nurse adheres to infection control practices, which is fundamental in healthcare settings. This helps prevent the spread of germs and protects both the patient and the healthcare provider from potential infections.

While providing an emesis basin would be a logical next step to manage the patient’s nausea and facilitate any possible vomiting, it cannot occur until after proper hand hygiene and appropriate protective equipment like gloves are in place. Documenting findings is important for medical records but is not an immediate intervention for the patient's current complaint. Obtaining vital signs, while also relevant for assessing the patient's condition, should follow the initial steps of ensuring safety and cleanliness. Thus, the correct first action is to wash hands and put on gloves, setting the stage for safe and effective patient care.