Public libraries have become a vital treatment site for overdoses.

Last year, Denver’s Central Library trained 350 staff members, more than half its personnel, to administer naloxone, the powerful drug that can reverse an opioid overdose.

“The death that we had in the central library was the moment when people in the library system said this is needed, this is serious,” says Denver libraries' spokesman Chris Henning.

Last year alone, Denver library staff successfully reversed 13 overdoses using naloxone. They are being trained to spot the symptoms of an overdose, including loss of consciousness, a choking sound, and fingernails and lips that turn blue or purple. Fortunately, if naloxone is administered to someone who is not experiencing an opioid overdose, the drug doesn't harm the person.

Health experts say it was inevitable that librarians would become involved in the nation's opioid crisis.

“One of the great things about libraries, if you are homeless or transitionally housed, is you don’t have to purchase anything to use the library -- and the bathroom is unlocked. So it’s a place where people can and will inject themselves,” says Lisa Raville, executive director for the Harm Reduction Action Center in Denver.

Libraries in New Orleans, Philadelphia, San Francisco and Salt Lake County, Utah, among others, are also stocking the overdose reversal drug. When overdoses in libraries became a regular occurrence in New York state, Gov. Andrew Cuomo signed a bill authorizing them to carry naloxone; libraries in Suffolk County and Middletown have since started.

U.S. Rep. Sean Patrick Maloney of New York introduced a bill last year that would award federal grants to libraries that want to administer naloxone. The bill hasn’t moved past the House Energy and Commerce Committee.

For some cities, those federal grants are needed. Last year, Baltimore stopped giving naloxone to all police officers, who are often the first to respond to overdoses. In October, the city asked the White House to help maintain its naloxone supply. The White House didn't commit to assisting the city.

Denver Public Library spent $1,800 on naloxone kits in 2017. Each kit typically comes with two applications, costs between $75 and $125, and is administered through a nasal spray. The injectable version costs about one-third of the nasal application but requires additional training, says Raville.

Naloxone works quickly, but it's often only a temporary fix. Without additional medical attention, a person can slip back into an overdose. So library staff are trained to call paramedics once they suspect an overdose.

Treating overdoses is just the latest way in which librarians have seen their role transform in recent years.

In 2016, a branch of the Philadelphia Free Library added a pediatric and primary care clinic on its top floors. Branches across the city offer seniors help enrolling in Medicare and offer nutritional guidance to immigrants and low-income families. Libraries in Denver, San Francisco and New Orleans have all hired or created partnerships with social workers to help the homeless and people with mental health or addiction problems connect to services.

“Libraries have always been a community gathering place," says Paul Guequierre, director of communications for the Urban Libraries Council. "What we are seeing is that in the past 15 to 20 years, we have a shift away from the 'Quiet, Please!' signs to a true gathering place."