For the first time in a couple years, New Jersey Blood Services has declared a "blood emergency" for a lack of donations and reserve supplies on hand.

The organization has dipped below a seven-day supply of blood overall. There's less than a one-day supply on hand for Type O Negative, which can be donated to anyone.

"We're anticipating that we're going to be extending this emergency appeal through the July 4th weekend," NJBS Director Marie Forrestal told Townsquare Media New Jersey.

The warmer months are typically accompanied by a drop in donations, but an "emergency" hasn't been declared by NJBS, a division of the New York Blood Center, in about two years.

During the summer, individuals may skip out on a blood drive because of the heat, or they're halfway across the country on vacation. Twenty percent of NJBS blood donations come from students, so when schools and college are on break, groups experience a big dent in collections.

"Every two seconds, somebody's using blood. And one out of every seven patients that goes into the hospital is getting a transfusion," Forrestal said. "Those numbers are staggering, so we're asking people to donate or host a blood drive."

About 20 percent of the blood collected comes from their donor centers in New Brunswick, Scotch Plains and Paramus, Forrestal said. A center in Raritan accepts platelets only. The rest comes from blood drives at locations such as schools, corporations, community groups, and houses of worship.

"If there's a group that has more than 200 people, we are trying to urge them to have an on-site blood drive," she said. "If there's a blood drive that's convenient and close, I would urge someone to make at least one blood donation this summer."

NJBS aims to collect more than 250 units of blood on a daily basis. Hospitals have a standing order, but 'stat' orders are also needed in times of crisis.

According to the New Jersey Hospital Association, fewer than 4 percent of the state's eligible blood donors took the time to donate in 2017.

In New Jersey, individuals who are 17 years of age (16 with parental consent), weigh at least 110 pounds and are in generally good health may donate blood. People are eligible to donate a pint of blood every 56 days.