Maintaining an environment that minimizes stress on poultry is a significant part of obtaining a healthy bird that reaches its full genetic potential. One challenge that producers face is preventing heat stress and maintaining performance in hot weather conditions. By keeping bird body temperature, which slightly increases from 39°C to 41.1°C as the chick grows and develops, in the normal range, the bird will continue to grow, develop and efficiently utilize the feed that it consumes. The focus of this chapter will be on the principles of poultry management that farmers can implement in their poultry houses during hot weather to prevent heat stress and maintain normal bird body temperature. Ventilation, evaporative cooling and management practices that influence the ability of the farmer to keep birds cool will be reviewed.