"The venomous nature of this species is substantial and a sting from the red lionfish constitutes a serious health emergency. Localized symptoms of envenomation by the red lionfish include but are not limited to, persistent, intense, throbbing, radiating, sharp pain at the site of envenomation, tingling sensations, sweatiness, and blistering. The worst cases of envenomation may cause systemic repercussions including headache, nausea, vomiting, abdominal pain, delirium, seizures, paralysis of limbs, a rise or drop in blood pressure, respiratory distress, heart complications including congestive heart failure, pulmonary edema, tremors, muscle weakness, and loss of consciousness. Basic treatment includes immersing the afflicted area in hot water (to 45° C) as past case histories informally indicate that certain components of red lionfish venom may be inactivated by heat. Professional medical attention should be sought in any case of red lionfish envenomation.
The red lionfish is aggressive, even engaging potential threats with a spines forward approach. This species should be treated with care at all times. Worldwide, scorpionfishes rank second only to stingrays in total number of envenomations, with an estimated occurrence of approximately 40,000 - 50,000 cases annually."
http://www.flmnh.ufl.edu/fish/Galler...RLionfish.html