William is undergoing chemotherapy and like many kids at the IWK, he's losing his hair (Phonse Jessome/CBC)

All four-year-old William McGill wanted while undergoing chemotherapy was a ball cap and now, thanks to the generosity of strangers, no one else at the IWK will have the same problem.

William is undergoing chemotherapy and is losing his hair. His mother Lesley said he went hunting for a hat at the hospital to cover his head.

But when they dug through the children hospital’s toy box there wasn’t a lot to choose from.

"Lots of winter hats and lots of girly hats with bows that wouldn't suit him so he was disappointed the first day we went and dug in the box," she said.

She called Farmers Dairy and the staff donated close to 70 hats in a single day. Other companies jumped in and soon the box was teeming with caps.

Other patients at the IWK are already sporting a new look thanks to William. Lesley said  the hats are a huge gesture for children undergoing treatment.

"Up until then he was a very outdoorsy little boy and being sick really took a lot of energy out of him and made him a very subdued young boy," she said.

In the end, William chose a hat close to home.

He went with a New Holland Agriculture hat because his dad works there, and because "I like New Holland tractors, they're blue."