A four-year-old Ontario boy with cancer has started a lemonade stand to raise funds for the hospital where he undergoes treatment.

Sam Cargill, of Ajax, was diagnosed with Stage 4 cancer in March when doctors told his family that the disease had spread to his lungs. He had a tumour and the kidney it was on removed at Toronto’s Hospital for Sick Children and has been on chemotherapy ever since.

When his mother Elizabeth Sokolowski asked him if he had any ideas of how he could “help the hospital that is helping him so much,” he knew exactly what he wanted to do.

“He immediately asked if he could have a lemonade stand,” she wrote on Facebook.

On Sunday, the family erected a blue tent on their Ajax home’s front lawn, set out a table with jugs of lemonade and posted signage reading “Sam’s Stand for Sick Kids” (with yellow T-shirts to match).

Plenty of local residents showed up, as did a parade of first responders. Firetrucks blared their sirens and brought Sam into the driver’s seat for some photos. “They stopped it and I hopped in it,” Sam recalled for CTV News Toronto.

“He was in heaven. Just a huge grin on his face,” said his mother. “Basically all of Ajax turned out. An incredible response from Ajax Fire, Police and EMS. It was unbelievable.”

For Durham Regional Police, it was a special moment that “came from the heart,” said spokesman Dave Selby. “This young guy really touched a lot of officers and they wanted to just go and say hi and support him,” he said.

Sam and family are already thinking they might bring back “Sam’s Stand for Sick Kids” for round two. “Just to see him have a moment of not thinking about things and just enjoy -- was wonderful,” said his mom.

Help for Sam has gone beyond just hospital staff. A GoFundMe campaign for the family has raised more than half of its $50,000 goal.