United Blood Services has issued an urgent need for donations of all blood types, especially O-negative, due to a stall in donations following severe winter storms across the country.

The nation's blood supply is already trying to recover from low donor turnout over the holidays, and the recent weather has increased pressure even more.

An estimated 84 blood donations couldn't be collected across Wyoming due to recent high winds, snow or early closures at five mobile blood drives across the state.

All blood types are needed, with O-negative -- the universal blood type that can be given to patients of any type -- needed most urgently. Type O-negative is often used for premature infants and in emergency situations when there is no time to type and cross-match the patient.

Platelet donors are needed as well. Platelets are used to treat patients undergoing chemotherapy, and their shelf life is very short -- only five days -- while whole blood or red cell donations can last 42 days.

Those wishing to donate must be at least 16, weigh a minimum of 110 pounds and be in good health. Donors who are 16 or 17 must have a signed permission form from a parent or guardian, and additional height and weight requirements apply to donors who are 22 years old and younger.

For more information on requirements to donate, click here.

It only takes about an hour to donate, from check-in to refreshments. Donors who complete their Fast Track Health History Questionnaire a day before they donate can shave about 20 minutes off that time.