The usefulness of counting 'heat-affected' red cells as a guide to the risk of the later disappearance of red cells after burns.

The technique for counting heat-affected red cells (;microcytes') in the head of the blood film taken from patients on admission is described. Although crude, it does appear to increase the precision with which it is possible to predict the disappearance of red cells in the first 24 hours after a burn, and therefore to decide those cases in which (51)Cr red cell volume estimates may be clinically useful.