From January and into February, the Red Cross, which supplies about 40% of the nation’s blood, reported a critical blood shortage nationally.

Since then, donations have gone back up, but officials say they are as important as ever. In the U.S., someone needs a blood transfusion every two seconds.

“It doesn’t occur to the average person. Most of us don’t realize the need for blood until we need it,” said Dan Dowling, regional communications manager for the Red Cross in Northern New England. “It’s the blood that people donate today that goes to help people tomorrow. You can’t manufacture blood. You can’t stockpile blood.”

Dowling said the U.S. is in constant need of blood, be it to treat victims of accidents or those with long-running illnesses. This need is exacerbated by blood’s relatively short shelf life.

So, he encourages everyone to get involved. Here’s how you can in Maine.

Who can give blood?

To donate blood in Maine, you must be at least 16 years old and weigh at least 110 pounds.

You must also be in good health, and every time you donate blood you’ll undergo a health screening that involves checking your temperature, blood pressure and iron levels.

Dowling said a common misconception is that blood type matters, or that donors need to know their blood type. In fact, all a donor needs is some form of photo identification.

People are eligible to give blood, at most, six times a year (every 56 days), and the whole process takes about an hour from start to finish. But the donation itself — the part that involves a needle — only takes about 10 minutes. It’s quickly followed by juice and a snack, and shouldn’t massively impact the rest of your day.

The Red Cross advises those who have just given blood to avoid strenuous activities, as they may tire more easily, but they’re otherwise free to go about their routines as usual.

“We hope that people leave feeling like they did something good,” Dowling said. “Feeling like they made a difference at the end of the day.”

What about platelets?

If you’re giving platelets, the smallest component of your blood, which stop bleeding, you won’t need any recovery time. But you will need a longer window for giving.

People can donate platelets every seven days, up to 24 times a year, and the whole process takes about 2 1/2 hours. It involves a needle in each arm, and a machine which separates platelets from the rest of the blood before putting the remaining blood back in the donor’s body.

Platelets only have a five-day shelf life, so they’ll likely be in use the same week someone donates them, Dowling said. Nearly 50% of donated platelets go to cancer patients, who experience low platelet counts during treatments.

What if I’m not eligible to give blood?

If age, weight, a fear of needles or a health condition mean you’re not eligible to give blood, this doesn’t mean you can’t help.

Community organizations can host blood drives, and you can easily coordinate one with the Red Cross. Or, volunteer at a blood drive. This could mean checking people in, making sure they get to the right places or delivering snacks.

“I see it happen all the time,” Dowling said. “It’s just as important and just as gratifying as being a blood donor themselves.”

Until May 17, the Red Cross will give a $20 Amazon Gift Card to donors, and from May 18-31, donors will receive a Red Cross beach towel.

To donate blood in Kennebec County this month, visit any of the following blood drives:

In Augusta, head to The Augusta Elks Lodge at 397 Civic Center Drive from 11:30 a.m. until 5 p.m. on May 11 and May 18.

In China, a blood drive is planned at American Legion at 79 Legion Memorial Drive from 9 a.m. until 2 p.m. May 16.

In Litchfield, The Litchfield Fire Department will have a blood drive at 2400 Hallowell Road. from 9 a.m. until 2 p.m. May 23.

In Waterville, O’Brien’s Event Center at 375 Main St. is set to host a blood drive from 9 a.m. to 2 p.m. May 15.

In Winslow, find a blood drive at Winslow VFW, at 175 Veterans Drive from noon to 5 p.m. May 13.

In Winthrop, a blood drive is scheduled at Winthrop American Legion, at 117 Bowdoin St. from 11:30 a.m. to 5 p.m. May 12.