As a followup to Jason’s advice, you can contact the Red Cross for information about the nearest location to give blood. Their server is completely overloaded, and I can’t get through to 1-800-GIVE-LIFE, but they’re going to continue to need blood over the next few days. (The eligibility guidelines are very slow coming up at the moment, but if you’re above 110 pounds, don’t have a tattoo or bloodborne diseases, aren’t currently sick, and haven’t spent more than a few months in Europe in the last few years, you’re probably fine.) Here is the Google cache of their page; I hope that when things are slightly calmer, I can get through, find a location, and donate on my lunch hour.