Can chickens suffer from heat stress?
Andy Cawthray says: During the hot summer months it is essential that chickens have access to shade. They are a jungle animal in origin, and, whilst they do cope with warm weather, they do not have sweat glands. Their thermoregulation is done using heat transfer through the comb, wattles, and nasal cavity. They will also pant and may even loose feathers (even if they are not due to moult). Egg production also drops if the temperature is above 27°C (80.6°F) for a prolonged period of time.
Chickens will eat less, move less, and grow less during very warm weather, and may give the appearance of drooping as they drop their wings away from the body in an attempt to increase air movement and body heat loss.
Heat stress is particularly important to consider if transporting a number of birds during the day. If the chicken is exposed to temperatures exceeding 40°C they can die within 15 minutes.