What toxicity may result from the xenobiotic responsible for the finding on this plain film? Answer: reduced iron, found in heating pads and instant hand warmers, may result in elevated serum iron concentrations and subsequent iron toxicity.

Disposable heating pads are commonly used products, with reduced iron as their active ingredient. Reduced iron is not expected to cause significant toxicity when ingested orally. We report a case of accidental heating pad ingestion seen on abdominal plain films that resulted in significantly elevated serum iron concentrations.