The most important factor to control in the first hours and days is the body temperature of the day-old chick. Only when this body temperature is correct, the bird will be able to find feed and water. This body temperature can be controlled with an infra-red ear thermometer, placed on the cloaca, and should be 40oC or 104oF. Also measuring deep body temperature by inserting a thermometer in the cloaca will give an accurate reading.

Day-old chicks are not able to control their own body temperature. Their thermo-regulation is so called poikilotherm, which means that it fluctuates with the temperature of the environment. Only at an age of 4-5 days, the thermo-regulation is at homeotherm state, which means that within limits, the bird can influence its own body temperature. Chicks of young breeder flocks (before 30-32 weeks of age), have a limited and delayed transition from poikilotherm to homeotherm.

To control the body temperature during the critical phase of poikilothermy, measure the birds approximately 2 hours after arrival and repeat for several times during the first day, to ensure the birds remain at the right body temperature. Check each time approximately 50 birds in total, divided in 5 groups of 10 birds at different places in the house. The main trigger for controlling the body temperature is limiting the heat loss through the floor.