Birds, like other warm-blooded animals can overheat. This most commonly occurs if:
The bird is kept in a cage in direct sunlight where there is no shade or shelter from the sun.
A bird is in a vehicle with the windows closed or with inadequate ventilation.
Too much supplemental heat, in the form of a heat lamp or heating pad, is supplied.
The bird is wrapped in a towel (a common method of restraint) for too long of a time period.
Overheating tends to occur more commonly in birds that are overweight, so keep your bird at her optimal weight.
Signs of heat stress or heatstroke
Signs of heatstroke in a bird include:
Panting (open-mouth breathing)
Holding the wings away from the body
Anxiety or agitation
Heatstroke can be fatal, so prompt attention is required.
First aid for heatstroke
To treat a bird with heat stress or heatstroke:
Move the bird to a quiet, cooler location
Mist the bird with water until his skin is wet
Keep the bird's feet and legs moist with cool water
Do not additionally stress the bird
Monitor the bird closely and contact your veterinarian