 At science fiction conventions to receive his autograph, fans would be asked to co-sign with Heinlein a beautifully embellished pledge form he supplied stating that the recipient agrees that they will donate blood.He was the guest of honor at the Worldcon in 1976 for the third time at MidAmeriCon in Kansas City, Missouri.At that Worldcon, Heinlein hosted a blood drive and donors' reception to thank all those who had helped save lives.