Hundreds of people will sleep at the Phillies ballpark on Nov. 20. Here’s why.

On a November night a few weeks after the baseball season ends, the outfield at Citizens Bank Park will be filled with people in sleeping bags.

The Phillies are partnering with Covenant House, a nonprofit that provides services for young people experiencing homelessness, for a "sleep out" fundraiser on Thursday, Nov. 20, when participants will stay at the ballpark from 7 p.m. to 7 a.m.

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"It's not a slumber party. It's not a camping trip. It's not pretending to be homeless," said Colleen Veldt, Covenant House's vice president of peer-to-peer fundraising. "It's really a very strong act of solidarity to call attention to this issue and to raise money."

Covenant House operates in 19 states and five countries providing shelter, housing support and other resources to people ages 16-21 who are on the street or have been victims of human trafficking. The organization is celebrating its 25th anniversary in Pennsylvania and wanted to revisit a yearslong partnership with the Phillies, who once had former managers Charlie Manuel and Larry Bowa spend a night on the street in Center City to raise money for the nonprofit.

Covenant House, based in New York City, once had a sleep out at Yankee Stadium with about 250 people on the field overnight. The organization hopes to bring about 750 people to Citizens Bank Park this year, making it the largest sleep out event to date. Covenant House also will host events nationwide the same night, including smaller sleep outs at MetLife Stadium in New Jersey and Gillette Stadium in Massachusetts.

"The premise of the event is that you're giving up your bed for one night so that a young person facing homelessness can have a safe bed at Covenant House," Veldt said.

Covenant House estimates more than 4.2 million young people experience homelessness in the United States each year, including more than 10,000 children and youth in Philadelphia and over 46,000 statewide. Many young adults lose their safety nets when they age out of the foster care system. Others struggle with mental health and legal issues. Some lack basic documents needed to access housing and other necessities.

"It's a less visible population than the adults who are facing homelessness, and that's really part of the issue," Veldt said. "Young people are really good at flying under the radar. They have really been let down by the adults and institutions in their lives, so they're hesitant and afraid to come forward to ask for help. They couch surf and try to make it on their own as long as they can."

People who want to participate in the sleep out at Citizens Bank Park must be at least 13 years old and will need to raise a minimum of $1,000 using Covenant House's fundraising portal. Those who sign up for the event can customize their pages and share links on social media, in group texts and by email to raise money.

"Our team gives weekly coaching tips to try to make it as easy as possible for them," Veldt said.

On the night of the sleep out, Covenant House will provide participants with a sleeping bag, a cardboard box and light refreshments. All minors must be accompanied by a parent or guardian. The event will go on rain or shine. Based on the weather or the amount of space occupied in the outfield, some people will sleep in covered areas of the ballpark concourse. There will be access to bathrooms and Covenant House staff will be available to offer emotional support.

"It's meant to be uncomfortable. It's a challenge," Veldt said. "It's not homelessness by any stretch of the imagination, but it's not usually a comfortable night."

The morning after the sleep out, Covenant House leaders and alumni who once stayed at the organization's shelters will hold a reflection period for people to talk about their experiences. Holding the sleep out on Thursday is an intentional way to help people understand the difficulty of going to work or school after a night without their usual comforts.

"You get a full, immersive experience in our work, our mission and our world when you come to our events," Veldt said.

Covenant House has a 24/7 youth crisis center and shelter in Germantown that serves about 300 people every year. The nonprofit also has additional beds at other locations in the city, a mobile outreach unit and a transitional housing facility serving youth in York.

Veldt said the Covenant House's goal is to bring in more than $1.5 million from the sleep out event at Citizens Bank Park. All proceeds from the event will support young people in Pennsylvania, and those who wish to participate in the sleep out virtually from another location also are invited to sign up.

"We want people to know that this is a really pressing issue and that there is something they can do to help," she said.