Potatoes naturally produce small amounts of a toxin called solanine as a defense against insects.
But prolonged exposure to light and heat increases solanine production and can cause potatoes to turn green.
Eating green potatoes can cause fever, headahce, vomiting and diarrhea.
Boiling, but not baking, usually removes most of the solanine from potatoes. But as a rule, it' s best not to eat potatoes if they are green.
To help keep potatoes from turning green, store them in a cool dimly lit place.