LifeSouth Community Blood Centers need blood now.
There is an emergency need for O-negative blood, said Galen Unold, LifeSouth's director of donor recruitment.
"When we go into an emergency need, that basically means that we do not have any blood on our shelves," he said.
Because of the shortage, hospitals receiving blood from LifeSouth have less than a two-day supply, but should have enough for three to five days, Unold said.
LifeSouth provides blood to hospitals in Florida, Georgia and Alabama. The organization tries keeping at least a five-day supply of blood on its shelves.
Group O donors can provide red blood cells for anyone, according to the American Red Cross. O-positive is the most common blood type and O-negative is the rarest. About eight percent of Caucasians, four percent of African-Americans, four percent of Hispanics and one percent of Asians are O-negative.
The shortage is caused by a combination of factors, such as low donations over the holidays and high blood usage at hospitals. Students account for 25 percent of donors, but they donated much less during the winter break.
"Less people were giving blood, that's really what it came down to," Unold said.
Blood use in hospitals also increased 15 percent. This could have been from the flu or more trauma accidents, Unold said.
LifeSouth needs 305,000 donations every year to keep up with demand. About 276,000 donations occurred last year, according to the company's 2012 annual report.
Last week, emergency donations were needed for type O-negative, O-positive and A-negative.
UF freshman Diego Hitch, 19, donated blood for the first time last week because he wanted to contribute. He is O-positive but didn't know about the shortage.
"You never know when it's your own life at risk, and you need blood," he said.
One donor gives about a pint of blood. In order to make up for the shortage, LifeSouth needs to receive 185 units of O-negative Monday and Tuesday.
The "What Colors Do You Bleed?" campaign, hosted by Gators Bleed Orange and Blue and the UF and Santa Fe College Blood Drive Advisory Councils, began Monday and ends Friday.
Three LifeSouth bloodmobiles will be on the UF campus from 10 a.m. to 5 p.m all week.
The campaign is a competition against the University of Kentucky to see what school can draw the most donors the week before the Feb. 12 UF-UK basketball game.
The campaign is trying to get 1,400 donors, said Clay Gibbons, a community development coordinator for LifeSouth and the Gators Bleed Orange and Blue advisor.
Gibbons said the campaign should get blood levels back to the shelves for three to four days.
During last year's competition, 1,393 donors gave blood.
Donors must be at least 17 years old, or 16 with a parent's permission, weigh 110 pounds and be in good health.
"If everything goes according to plan, it would get us out of the emergency need," Unold said.
Auriel Rolle-Polk reported for broadcast. Mina Radman edited this story online.