Fresh tuna (also called Ahi) – tuna that is just caught – must be handled properly, whether it ends up at the seafood counter or in the canning factory. Failure by fishermen or harvesters to chill the tuna to at least 60 degrees F (15.5 degrees C) immediately after catching allows a toxin called Scromboid to contaminate the fish. Scromboid causes dizziness, hot flashes, swelling of mouth and lips, abdominal cramping, vomiting, and other nasty symptoms. These toxins generally CANNOT be cooked out of the tuna. In addition, it is virtually impossible to determine if the tuna has been contaminated before consuming it. So choose your tuna wisely!