Looking for a way to help out humanity amid the COVID-19 pandemic?

Hold out your arm.

On Thursday, the keepers of the blood supply at Maine Medical Center in Portland downgraded their inventory status from “yellow” to “orange.” Which, as Dr. Timothy Hayes, medical director of the hospital’s blood management program, noted in an email to the hospital’s Transfusion Committee, “is just a shade shy of RED.”

The alarm is going off in hospitals everywhere in this era of shortages brought on by the novel coronavirus: We as a nation are fast running out of blood.

“Yesterday, for example, I think we gave out 50-some-odd units of packed red blood cells – and we got 20 back from the American Red Cross,” said Dr. Joseph Rappold, chief of trauma at Maine Medical Center and chairman of the Transfusion Committee, in an interview on Friday. “So that math just doesn’t work.”

It’s a simple matter of supply and demand.

Back in March, as the pandemic put the country into lockdown, both ends of that equation plummeted. Widespread cancellations of blood drives put a sudden crimp on the blood supply, yet simultaneous postponements of nonessential surgery, coupled with drops in trauma cases because fewer people were out there getting hurt, drove down the demand for blood as well.

Not so now. As hospitals return to normal and catch up on surgical backlogs, that demand has spiked sharply. The supply, however, hasn’t.

“We’re starting to get into a critical situation,” Chris Hrouda, president of biomedical services for the American Red Cross, told The New York Times earlier this month. Inventories, he said, “have been cut in half” by the pandemic.

The Red Cross, which provides 40 percent of the nation’s blood supply, has reduced normal distribution of red blood cells, plasma and platelets to hospitals by 25 percent. If donations don’t increase soon, Hrouda warned, fulfillment of standing hospital orders for blood could be cut by half.

Challenging as the situation is here in Maine, it would be worse if not for efforts by the business community to offset the dearth of local blood drives, many of which typically took place in workplaces that have been shuttered for months.

“Distance Saves Lives,” a donation program organized by MaineHealth and sponsored by 25 Maine businesses and organizations, just exceeded its goal of collecting 1,000 pints of blood, according to Caitlin Loveitt, MMC’s director of marketing and coordinator of the program.

The blood drives, held by appointment only each Wednesday from 10 a.m. to 4 p.m. at the Portland Elks Lodge on outer Congress Street, began on April 1 and initially were scheduled to run for 10 weeks.

“But we’ve had so much interest from the business community that we were able to extend it another four weeks to July 1,” Loveitt said.

Each week, a sponsoring business puts out the word encouraging its employees to donate. But with the average number of appointments currently filling about 95 of the 120 available slots, Loveitt noted, there’s still room for others.

Mary Brant, external communications manager for the American Red Cross Northern New England Region, said in an interview on Friday that there’s a long way still to go to offset the 13,000 units of blood normally collected daily nationwide by the Red Cross.

But opportunities are still out there, she said, including some 40 blood drives scheduled in southern and central Maine through the end of June. To make an appointment or find a drive, call 800-733-2767 or go to www.redcrossblood.org.

“Coronavirus or not, the need for blood is constant,” Brant said. “It doesn’t stop – even for a pandemic.”

Still, the pandemic has stopped blood donors, who comprise a paltry 3 percent of the American population. From stay-at-home orders to a general aversion to public places, many people who might otherwise donate as frequently as every eight weeks now find themselves reluctant to go anywhere – let alone someplace where they’re going to have a needle stuck in their arm.

They might want to reconsider.

“The difference that donors will see is that no one – and that’s either staff or donors – enters without having their temperature taken,” Brant said. “And everyone is required to have a mask. If donors do not have a mask, one will be provided to them.”

Beyond that, risk-mitigation procedures include social distancing, constant disinfection of high-touch surfaces and appointments to prevent human traffic jams.

In other words, the danger of exposing oneself to the coronavirus via blood donation is minimal. Conversely, for those eager to do something, anything, constructive in this time of widespread angst, what could be more therapeutic than spending 15 minutes saving another person’s life?

It could be a trauma victim who arrives at the emergency room bleeding heavily from a stab wound, or injuries sustained in a high-speed crash.

In such a case, MMC trauma chief Rappold noted, “We could easily go through 30 to 50 units of packed red blood.”

Or it might be a cancer patient whose daily blood transfusions are the ticket to living to see another day.

As Dr. Hayes warned in his email to MMC’s Transfusion Committee last week, “We may be forced to limit transfusions to those patients who are transfusion-dependent (e.g., oncology patients), and even these patients may not get the blood that they need to survive.”

He added somewhat ominously, “We should start discussing plans in case the worst materializes.”

Finally, there’s the simple reality that the shelf life for donated blood is only six weeks – meaning today’s entire supply must be replicated no later than the end of next month.

So, fellow Mainers, if you’re healthy and able and have never donated before, now is the time. And if you’re a regular who’s fallen out of the habit, they need your outstretched arm more than ever.

“This is the first time we’ve seen the American Red Cross really ring the bell,” said Rappold. “We have a very bad potential problem here.”

Indeed. But unlike the pandemic that triggered it, it’s a problem that’s easily solved.