CDPH said it is urging residents not to forage for wild mushrooms after poison control confirmed a cluster of amatoxin poisonings linked to death cap mushrooms that includes 21 cases and one adult death.Erica Pan warned that cooking, boiling, drying or freezing will not render death caps safe and said symptoms often begin 6 to 24 hours after ingestion, may briefly subside while liver damage progresses and can lead to serious or fatal liver injury within 48 to 96 hours, and officials urged buying mushrooms from reputable sellers and calling the poison control hotline at (800) 222-1222 for guidance.