Canadian Blood Services is urging people to make room in their busy holiday schedules to donate a unit of blood.

Donations drop dramatically around Christmas and over the holidays, said the director of donor relations in B.C. for Canadian Blood Services.

"It's a time when people have lots of things to do, they're taking time off work… They maybe forget about patients who are spending their holidays in hospital," said David Patterson.

He said he has 3,700 vacant donation appointments in B.C. to fill before Jan. 7.

"There is an urgent need for blood donors this time of year," he said

It's incredibly important to get regular donations throughout the year, since some blood products expire quickly, Patterson said. Platelet products, for example, only last one week after blood is harvested.

He tries his best to fight against seasonal drop-offs because people need blood products 365 days a year.

One of those people is Lily Hall. The 16-year-old has two tumours in her brain and one in her spine. She has seizures nearly every day.

"She's had three different kinds of chemotherapy to tackle this tumour," her mother Hollie Hall said.

In February, Lily learned her chemotherapy had caused pancreatitis. She became very sick and her immune system was weak. Doctors decided they had to do a blood plasma boost—twice.

"The doctors said it was like changing the oil in your car," said Lily's father Chris Hall.

After receiving the blood products, Lily's parents noticed right away she seemed more awake. Then her white blood cell count came up, too.

"Thank you, that's all I can say," Lily said of the donors who gave their blood. "I wouldn't be alive."

Lily's parents have spent three years taking her for treatment at the oncology ward at BC Children's hospital. Hollie says kids with cancer need blood and pasma transfusions "all the time."

"It's life or death," she said.

This year, the best gift for some children is one that keeps them alive.

With a report from Breanna Karstens-Smith