If a person has swallowed a poison, when should you not make them vomit?

Making someone vomit after they have swallowed poison can be a crucial decision that depends on the type of poison ingested. If the ingested substance is corrosive, such as strong acids or bases, inducing vomiting can exacerbate the damage. This is because inducing vomiting would expose the esophagus and throat to the corrosive substance again, potentially leading to further injury.

The other options present situations where making someone vomit might still be permissible, though caution should always be exercised, especially if the type of poison is unknown or if the person is conscious and alert. In those cases, the physiological state or awareness of the person does not inherently make it safe to induce vomiting without knowing the nature of the poison. Thus, the specific danger associated with corrosive poisons makes it critical to avoid the act of vomiting in those scenarios.