Chera Kowalski is 33-years-old, working in the city as a librarian at the McPherson Square Branch Library. She goes into the square June 1, 2017 to help a woman who was thought to be overdosing. Police were called, but the women ending up being okay. In two months Kowalski has now saved seven lives. TOM GRALISH / Staff Photographer

On her last three shifts at the library in McPherson Square, Chera Kowalski has helped save the lives of three people overdosing on heroin.
She and the other librarians at the Kensington branch had told me two weeks ago that they feared that when the weather warmed, the crisis on the library lawn would grow worse than they could imagine.
It has.
Kowalski, 33, who keeps the overdose-reversing drug, Narcan, behind the circulation desk, has run for the spray as many times in the last week as she did last month. In two months, she has helped save eight people. It is becoming as much a part of her daily routine as finding reference numbers and helping students log on to a computer.
And each day the crowd of young heroin users on the lawn – from all over, with cardboard boxes and sleeping bags and wheeled luggage – grows.
And so do the national …