A case of hypothermia in turkey-poult embryos in the hatcher is described. Zoohygienic measurements have shown a variability in the basic microclimatic parameters, mainly of temperature, air movement and cooling power. The fact of overheating the embryos during hatching resulted in decreased indices of hatching as well as injury to circulatory and excretory systems of dead embryos. The number of the dead-in-shell embryos also increased in pipped eggs. Hypothermia had no significant effect on the increase in the number of turkey-poults with an unhealed navel.