When concentrated solutions get inside - severe burns of the digestive tract of the esophagus (with the subsequent development of strictures), hemolysis, hemoglobinuria; The lethal dose is about 3 g.
If you accidentally swallow unconcentrated solutions: abdominal pain, anuria, diarrhea with blood, severe thirst, fever, nausea, vomiting, metallic taste in the mouth. Shock, tachycardia, metabolic acidosis, renal failure. A fatal outcome is possible due to vascular insufficiency, epiglottis edema and asphyxia, aspiration pneumonia or pulmonary edema.
Treatment (if patient is conscious) - take milk every 15 minutes or a starch / flour solution (at the rate of 15 mg of starch or flour for 500 ml of water) to absorb unboiled iodine. You can also use Activated carbon and sodium thiosulfate (usually 1% solution) inside to transfer iodine to less toxic iodides. Gastric lavage is not recommended, as there is no certainty that even sufficiently weak iodine solutions can not cause a burn of the esophagus.To maintain the basic functions of the body - oxygen therapy, antihistamines, epinephrine and corticosteroids - with anaphylactic shock.