American Red Cross is currently facing a major blood shortage, and while I have some major issues with them as an org for a number of reasons, the unfortunate truth is that most hospitals get their blood products through ARC.
I know the hospital I work with has been forced to pause all major elective surgeries for 30 days because of this shortage (YSK: "elective surgery" does not mean "unnecessary surgery," it's a surgery that can be scheduled in advance, as opposed to emergency surgery).
I'm putting my monkey where my mouth is and donating on Monday, and if you meet eligibility requirements I urge you to do the same. You can download the ARC Blood Donor app to help coordinate finding a location near you with appointments.
for Red Cross locations, appointments are strongly encouraged but walk-ins are also welcome, you just risk having to wait or bring turned away if they're too busy at that particular moment with scheduled donors.
other options in WI include Blood Center of Wisconsin and ImpactLife locations (the latter serve WI and also IL, MO, and IA).
donations to locations that pay you for your donation do NOT go to hospitals.