Do you know your blood type and rh value? Without it, even 30 ml of the wrong blood and your dead. Even if you know (and especially if you don’t) you may want to get a bunch of Eldon cards (the liquid reagent is much cheaper but should be refrigerated). If you’re type AB+ (3 out of 100) you’ve won the lottery, you can get blood from everybody but you can only give to another person with the same blood. If you’re type O- (7 out of 100), then you can give to anybody, but you must receive from another O-. This way if you see some healthy looking refugees, and they want to join your group, you can add the value of their blood type to your assessment. The 7% that has type O- blood has added value for your group. – SF in Hawaii
JWR Replies: I also stressed the importance of blood typing in my novel “Patriots”. Even if you have a blood donor card, military identification card, or dog tags that indicate your blood type, it is a good practice to confirm it for yourself with an Eldon card. It is noteworthy that the blood typing error rate and the clerical transcription error rate are both alarmingly high in these records.