The team discover that one of the suspects suffers from hypothyroidism and that he will need regular medication or will die. The suspect is located when he gets some synthyroxine. Hypothyroidism is under-active thyroid. Although if untreated people can feel cold, gain weight, or feel depressed, untreated it is not a condition which is fatal. Synthyroxine AKA levothyroxine is the standard treatment and millions of people take it.