Tim Walz is coming back to Boston Wednesday. Here’s what to know.

Vice presidential nominee Tim Walz will speak at the 57th International Association of Fire Fighters Convention in Boston on Wednesday morning.

Walz will deliver remarks to one of North America’s largest labor unions, representing nearly 350,000 firefighters, emergency medical workers, and rescue workers in the United States and Canada.

“Governor Walz, a former union member himself, has a strong record of standing up for unions and delivering for workers — from joining the picket line and passing the most pro-worker package of laws in Minnesota history, to guaranteeing Minnesota workers [are] paid sick, medical, and family leave,” a statement from the Harris-Walz campaign said.

The 57th convention, held at Boston Convention & Exhibition Center in the Seaport from Aug. 25-30, will be Walz’s second appearance in Boston in two weeks, following his three-day solo tour which included an appearance at a fundraiser in Back Bay on Aug. 14.

Walz also stopped in Newport, Rhode Island, where the Catholic university that hosted the event faced criticism from the Diocese of Providence for doing so.

Vice President Kamala Harris and her husband Doug Emhoff have also made recent Massachusetts appearances, with Harris in Pittsfield after launching her own presidential campaign, and Emhoff in Martha’s Vineyard.

Gov. Maura Healy opened the firefighters convention, calling for national unity. 

“We may feel divided as a nation, at times we may not agree on everything, but today I want to underscore the importance of fostering national unity, and the firefighter’s commitment to service, community, and country is a powerful example and it’s something we can all unite around,” she said.