Don't do anything like that unless you know something about how to undo it.

Urging caution sounds wise, but I think it's exactly wrong here. One's goal in giving advice should be to alter others' behavior in beneficial ways; people will probably tend to take fewer risks with emetics than is optimal (because they're risk-averse, and vomiting is unpleasant), so your advice is in the wrong direction. Caution (higher significance criterion) is the act of increasing missed opportunities (false negatives) so that you take less wrong actions (false positives); this is a tradeoff.

This is analogous to how, for instance, the FDA kills more people by delaying medications' approval than it saves by ensuring medication is safe before approving it.

All over this thread, people keep urging caution where my judgment is that they should be urging the exact opposite.