The air circulation, dust levels, temperature, relative humidity and concentration of gases in the air must be such that they do not harm the animals. Ventilation levels as well as indoor conditions must be such as to provide clean air for the birds and the litter to be kept dry and crumbly. Air quality, including levels of dust and concentrations of carbon dioxide, carbon monoxide and ammonia, must be controlled and maintained at levels that do not harm animal health. In particular, ammonia levels should not exceed 20 ppm.

Records of the maximum and minimum temperature must be kept regularly. Sharp temperature fluctuations must be avoided. The birds must be protected from sudden frosts. Ventilation systems are a must to function in such a way as not to cause sudden temperatures changes.

When delivering the chicks, they must be placed on a special place and be monitored. Small chicks are particularly susceptible to extreme changes in temperature. After 4 – 5 weeks of age the birds are more tolerant to temperature fluctuations, but measures must be taken to avoid cooling, which would lead to crowding and suffocation of birds. Birds that are fed sparingly are highly susceptible to low as well to high temperatures. If a decrease in temperature is predicted it is necessary to increase the amount of feed or to provide heating appliances.