“Giving a mask to a health care provider on the front line has more potential for a positive impact than wearing it around the grocery store,” says Conrad Amenta, director of policy and strategic initiatives at the California Academy of Family Physicians, which represents some 11,000 family doctors. Many of them have recently said they were running out of supplies and would welcome donations of personal protective equipment, including face shields, surgical gowns, nonlatex gloves, sanitizing gel and especially respirator-type N95 masks. “Please don’t just go walking into a hospital trying to drop them off,” Amenta says.

If you have a lot of protective equipment, try calling your state’s department of public health first. “They should know where larger quantities are most needed in your state,” Amenta says. If the state does not respond, or you have fewer than 100 masks, look up your county or city health department or your local hospital’s website; many organizations have begun posting how they’ll accept donations. If no information is listed online, call. If you know front-line medical workers personally, you could text them directly to arrange a drop-off, but priority should go to those most likely to encounter patients with Covid-19, such as E.R. workers. “If the doctor you know happens to be a dermatologist or something, your donation won’t go as far,” Amenta says.

“It doesn’t matter if the box is opened,” he says. (Note that N95 masks have an expiration date, which you should mention; public health officials have approved the use of some expired masks.) Amenta has heard from biomedical researchers who say they can potentially donate tens of thousands of masks, and from people offering a few dozen left over from purchases made during recent wildfire seasons.

When Amenta was setting up a donation form online, he wasn’t sure how desperate to be. So he asked one of the physician leaders on the association’s board: “If I have somebody who wants to stick a single mask in an envelope to donate, is that worth it?” The response he got surprised Amenta. “The board member told me, ‘Absolutely, they should send it.”