Canadian Blood Services says a lot of blood donors are cancelling their appointments to give because of the recent winter weather.

Two storms that brought a combined 50 cm of snow and record-setting low temperatures to Windsor-Essex in the first six days of the year have kept people home.

"If you're in the hospital and you need a blood product, you need it and it doesn't matter whether it's nice out or snowing or what's going on out there," said  Joan Hannah, community development coordinator for Canadian Blood Services. "So, unfortunately, the need never goes away even though we may not get as many donors as we would like."

Veronica Magee, public affairs officer for Canadian Blood Services, says there is "an immediate need for more O negative blood donors."

"Our national blood inventory means that no one is currently going without blood and we can draw on our reserves so that patients who need blood continue to get it," she said in an email. "However, we need the help of Canadians from coast to coast to replenish the O negative supply."

People with O negative blood are considered universal blood donors because patients of all blood types can receive O negative blood.

Donor Hannah Bisschops had to dig herself out to make her appointment Tuesday, two days after the snow stopped falling.

"The need is always going be there. Whether there's cold or not, people are still going to be in need of getting blood, so the cold is not going to stop me nor is anything else," Bisschops said.

Valerie Derbowka made it to her 70th donation Tuesday.

"It doesn't take that long to come in and to donate and they should come in to give because people need it," she said.

Making matters worse is the fact Canadian Blood Services branches across Canada say the holiday season traditionally brings with it a decline in donations.

Michelle Thibodeau Coates , a Canadian Blood Services spokesperson on P.E.I., said winter storms there hampered donations.

“We certainly had a few days where we struggled specifically in P.E.I. with the weather,” she said. “And many of our donors weren't able to make it into the clinics.

“It does cause some challenges and we know that we still have many months of this ahead. The need for blood is constant. One car accident can use up to 50 units of blood."