A patient presents with a black substance around her mouth but denies exposure to burning materials. What should you do first?

In this scenario, the first action should be to ask if the patient knows what the black substance around her mouth is. This approach is crucial because it seeks to clarify the situation directly from the patient, which can guide further management. Understanding the origin of the substance can help determine whether it is related to an external factor like a substance that might warrant specific treatment or intervention, or if it is something benign.

By gaining this information, the EMT can better assess the patient's condition and decide on the appropriate next steps, whether that might involve administering specific treatments, monitoring her vital signs, or providing reassurance. The inquiry can also help in identifying any potential toxic substance exposure that may not be immediately obvious.

Other actions may seem relevant, such as administering charcoal or providing oxygen, but these interventions require more information to ensure they are necessary and appropriate for this patient. A neurological assessment is an important part of the overall evaluation, but it is premature to conduct it without first understanding the context of the patient's condition.