Inventory of blood needs an injection of 150,000 donations by July 1 With summer’s unofficial kick-off approaching this May long weekend, Canadian Blood Services is calling on all eligible Canadians to roll up their sleeves for patients. Canadian Blood Services boosts the blood supply every spring to prepare for the summer, when routines are disrupted as regular donors join the thousands of Canadians who head outdoors or out of town to enjoy the warm weather. This year, a stormy winter and a wet spring have left inventory levels lower than normal. That means there’s enough blood on the shelves