The National Poisons Information Centre of the National Institute of Public Health and the Environment in the Netherlands in the past 2 years received dozens of requests for information about intoxication due to stings of the weever, Echiichtis vipera. The venomous apparatus of the weever consists of gill cover spines and 5 to 8 dorsal fin spines. The fish buries itself in the sandy or muddy bottom of the sea to wait for prey. The mixture of toxins that enters the skin upon contact with the spines causes a heavy local reaction, characterized mostly by pain, which untreated persists for 24 hours. An erythematous oedema may develop locally, spread over the entire extremity and persist for days. Systemic reactions are rare. Since the toxin mixture is heat labile, treatment is essentially simple: clean the wound and immerse the affected limb as soon as possible in warm water (45 degrees C) for 30 to 90 minutes. This makes the pain disappear.