The danger is death or injury by carbon monoxide poisoning.

VOA: special.2010.02.02

The Court of Inquiry, kept secret at the time, found the cause of death was poisoning by nerve gas.

BBC: Transcript: Trial and Error

Giery said the hospital's diagnosis at the time of death was that his illness was caused by food poisoning from ciguatera, a toxin sometimes found in large saltwater fish including grouper, red snapper and sea bass.

NPR: NC Airman At Center Of Rabies Case Was Outdoorsman

She died an agonising and slow death at home which, though it was never proved, bore all the hallmarks of poisoning by strychnine.

ECONOMIST: Literary history: Murderous man | The