MILWAUKEE (CBS 58) -- With the severe winter weather, blood supplies are taking a hit as donations slow. 

Versiti is urgently asking for blood donors, especially O-negative and O-positive, which are universal and can be used for all patients, including emergencies and trauma care. 

Versiti says platelets are in constant demand for premature babies and cancer patients, and they're only useable for five to seven days outside the body. 

If eligible, Versiti asks that you consider donating now before the weather gets worse. 

There are 11 locations:

• Greenfield: 7210 W. Edgerton Ave.
• Kenosha: 8064 39th Ave.
• La Crosse: 1800 Jackson St.
• Manitowoc: 619 Reed Ave.
• Marshfield: 508 N. Central Ave.
• Milwaukee (Versiti on King): 2153 N Martin Luther King Jr Drive
• Milwaukee: 638 North 18th St.
• Racine: 1120 S. Sunnyslope Drive
• Waukesha: 2111 Springdale Road
• Wauwatosa: 8733 Watertown Plank Road
• West Bend: 130 Valley Ave.

Anyone 17 years or older in good health and meeting eligibility requirements is encouraged to give. 

Donors should bring a photo ID that includes a birth date. 

Appointments are encouraged, but walk-ins are also welcomed. 

To schedule an appointment, click here or call 877-232-4376.