Early in the AIDS epidemic in 1984 Nicols' family discovered that he had been infected with Human Immunodeficiency Virus (HIV). The family did not disclose Nicol's infection in their small rural community of Cooperstown, New York, seeking treatment instead more than 200 miles away in New York City, where a child with AIDS might attract less attention. In 1991, when Nicols was diagnosed with AIDS and was told he had less than two years to live, he decided he should not keep his condition a secret any longer.
In the first ever planned disclosure in the United States of an American school student with AIDS, Nicols, with the help of then Cooperstown School Superintendent Douglas Bradshaw, made plans to reveal his illness to the Cooperstown community. On March 8, 1991, Nicols went public, holding a press conference at which he discussed his condition and declared that he would use his illness as a leadership project to earn the coveted Eagle Scout award from the Boy Scouts of America.
Unlike those who had preceded him, such as Ryan White of Kokomo, Indiana, and the Ray brothers from Arcadia, Florida who were shunned by their communities, Nicols was embraced and protected by his hometown of Cooperstown, New York. Nicols went from being an unknown and secret AIDS patient to becoming a local hero and an international AIDS advocate. He was featured on the cover of Parade Magazine, had stories written about him in People Magazine and numerous other news journals. He was a featured guest on Good Morning America and other national news broadcasts and was interviewed by CBS news anchor Peter Jennings during a TV special on AIDS. Nicols used his new found notoriety to advocate for compassion and understanding for all those afflicted with AIDS. Nicols completed the requirements to be an Eagle Scout and was awarded the Eagle Scout Badge in July 1991. He was awarded the first ever Ryan White Award by the National Hemophilia Association, testified before Congress and met with New York Governor Mario Cuomo and Arnold Schwarzenegger, then Presidential Physical Fitness Advisor to George H. Bush. Nicols also met with Presidents George H. Bush, and William Jefferson Clinton to discuss AIDS related issues. Nicols was awarded an honorary Bachelors degree from The University of Scranton in 1992. He was awarded the Caring award in 1992 by the Heart of America Foundation and Nicols and his family were featured in the 1993 HBO documentary Eagle Scout: The Story of Henry Nicols. Nicols, his sisters Jennifer and Diana and his parents traveled around the United States and the world to set up AIDS support groups. They worked in Ireland, Canada and Japan and met with university students in 42 states in the United States to educate and support those with AIDS.
As Nicols' illness progressed and his health began to fail he traveled less and less and, in the Spring of 2000 on his way to a Boy Scout weekend, Nicols had a one car accident, striking a tree. He died 11 days later at the age of 26. There are several monuments to his memory in Cooperstown, New York where his family still lives.