(USA Today) -- As flu and frigid weather force many people across the nation to stay bundled up inside, blood banks are reporting donors are canceling appointments and supplies are dropping.
"The American Red Cross is seeing a lower-than-expected turnout,'' says Stephanie Millian, director of biomedical communications at the American Red Cross. "We've even had seven blood drives canceled because of the weather in the Great Lakes area. Flu season is hitting us in other parts of the country. "
While none of the agencies responsible for collecting blood is reporting a shortage, they are experiencing low levels in several types of blood and are encouraging people to give blood if they're healthy.
About 1 in 7 people entering a hospital will require blood transfusions, according to America's Blood Centers. Blood is used to treat accident victims, cancer patients, hemophiliacs and surgery patients.
The greatest need is for O-negative blood, a type often called for in emergencies because it's a type any patient can use, says Millian. Only 7% of people are O-negative.
"We like to keep a five- to seven-day supply of all blood types on hand, and we're under a three-day supply now,'' says Jim Fox, director of communications at the New York Blood Center. Bone-chilling temperatures in New York fell into the teens this week, with wind chills below zero.
"When it's as cold outside as it's been here, most people like to stay indoors,'' Fox says. "But people with leukemia and other cancers don't have that option. They need blood transfusions. When we get weather like we've been having, we start to worry about supplies."
Mother Nature might help out soon. A warming trend is expected next week across parts of the nation. The flu is reported in all 50 states but is leveling off in many, the Centers for Disease Control and Prevention reported Friday. However some parts of the country, especially the Southwest and Northwest, are showing increases.
In Arizona, parts of Texas and in the Northwest, where United Blood Services serves hospitals, it is seeing a drop in donations and a rise in demand.
"We're struggling to fill blood orders for 145 hospitals in the Arizona area,'' says Sue Thew, spokeswoman for United Blood Services in Arizona.
Demand is above normal, Thew said, because hospitals delay many elective surgeries until after the holiday season.
"Hopefully, we can get everyone feeling better soon and back to giving blood,'' says Ashley Messick, communications specialist for United Blood Services. "It's not only people with the flu who are staying away but also their caregivers. We need to restock levels. We're meeting needs now by shifting blood around to areas where it's needed."
If you've had the flu, wait until you no longer have symptoms and are feeling well before you donate, according to the American Red Cross. Go online to make an appointment to donate: