Carol returns after her eight week absence, finding Doug holding himself responsible. Carter finds himself watching over a mysterious, mentally ill singing woman. Susan clashes with Dr. Kayson over a diagnosis. Dr. Greene treats a domestic violence victim.

The air conditioning quits on the hottest day in October which, coupled with closed ERs in Chicago's other two hospitals, leads to an extremely hectic day. Dr. Ross treats a six-year-old suffering from a cocaine overdose; Ivan Gregor, the liquor store owner, shoots and seriously wounds a young teenager. Susan's immature sister Chloe drops by, wreaking havoc in Susan's life. Doug picks up a pharmaceutical saleswoman, much to Carol's displeasure.

Carol worries about a Russian girl with AIDS who's brought in and then abandoned by her foster mother. Kayson asks Susan to be his Valentine. Deb accidentally consumes LSD-laced chocolates.

Dr. Ross treats the dying Chia-Chia. Susan tries to find a way to keep Little Susie, asking her parents for help. Benton treats an injured woman who refuses to press charges against her abusive policeman husband. Carol and Harper are tricked by a patient from the "turkey file." Lydia helps Loretta the prostitute outfit herself for a job interview. The staff celebrates Weaver's day off.