Which of the following is one of the first steps for an overdose or poisoning by ingestion?

In the case of an overdose or poisoning by ingestion, one of the primary and crucial steps is to identify the substance and the amount ingested. This information is essential for several reasons. First, it allows emergency medical personnel to understand the type of toxic substance involved, which informs the appropriate treatment protocol. Different substances have varied effects and treatment requirements; knowing what has been ingested can significantly impact the patient's management.

Additionally, identifying the amount helps to assess the potential severity of the overdose. Some substances may be toxic in small quantities, while others might have a higher threshold for toxicity. This assessment is vital for making decisions about the need for interventions like activated charcoal, antidotes, or other specific treatments.

In contrast, administering syrup of ipecac or inducing vomiting can be harmful, depending on the substance involved, and are not standard practices in many settings today given the risks they may pose. Providing warm fluids may not directly address the immediate priorities in managing an overdose situation. Thus, identifying the substance and amount ingested is the foundational step that leads to effective and safe treatment.