INDIANAPOLIS (WISH) — Central Indiana is experiencing the latest effects of this year’s crippling flu season, a critical blood supply shortage.

American Red Cross officials say the last time they had a critical shortage was last summer.

Right now, they only have a three-day supply left for the entire state.

“This is a very serious situation. It’s not a situation that we like to be in. But it is occasionally a situation at times of the year like this that we find ourselves in,” said Sandra Ryden with the American Red Cross in Indianapolis.

Ryden says a critical blood shortage is the highest level of alert issued for blood shortages.

The Red Cross tries to keep a five-day supply at all times to meet the needs of patients and to be prepared for emergencies. But recently, that’s been easier said than done.

“Critical shortage means less than a three-day supply. Then what would happen if we really got into dire straights or the hospitals did, doctors would start cancelling elective surgeries,” said Ryden.

One of the biggest reasons for the blood shortage this year is the flu. Local emergency room doctors say this year’s strand of the flu has hit hard.

“Just speaking from my experience from working in the emergency department in Indianapolis for a few winters, I can definitely say I’ve seen more flu tests come back positive,” said Dr. Holly Irwin with IU Health Methodist Hospital.

According to the Indiana State Department of Health, 31 people have died from the flu this season.

Health officials say the U.S. is on track for one of the worst flu seasons in decades, with the Center for Disease Control showing a good portion of the country showing high flu activity.

Officials with the Red Cross say they are feeling the trickle down effect.

As the flu season continues to ramp up, Red Cross officials are asking all blood types to donate.

“We have this terrible flu season going on right now, and so many of our donors are ill and they can’t come out or they’ve been exposed, or they have a sick child that has the flu and they just don’t want to carry that on to people that are in dire straights,” said Ryden.