Aunt needs a 4 liter blood transfusion does she have a chance to live?

My aunt was rushed to the hospital yesterday afternoon. My grandma said that the doctor told her that she needs to get a blood transfusion of 4 liters because she lost alot of blood. She wasn't bleeding out or anything so I don't really know why she needs so much blood. All that my grandma said was that she needed to have a lot transfused to her body and that they couldn't do it right away because she was having high fevers. Does anyone know what could cause this? Do you think that she'll live or no?