In the end of the incubation.

Carefully control the temperature regime in the end of the incubation. In this period embryos produce a great deal of physiological heat (especially in the incubators without forced ventilation).

If the temperature comes up above 38,6-38,8°Ñ, adjust it to the normal level: open the incubator or bring the tray with the eggs out of the incubator for some time and cool them down until the eggs have the normal temperature.