Episode 8 of "House"
s01e08 Poison

When a high school student falls victim to a mysterious but lethal poisoning, House and his team jump in to find out what is killing the teen. Given a low heart rate and a clean tox screen, House sends Cameron and Chase to the teen's home to find the hot new drug House is sure he's taking. They don't find any drugs, but think they've come up with the answers, until a second unrelated student is admitted with identical symptoms. With the boys' lives hanging in the balance, House and the team have to connect the dots – fast. Meanwhile, an 82-year-old patient has become enamored with House while he helps her figure out the basis of her renewed fascination with her sexual feelings.