Sick birds respond well to heat and quiet. A hospital cage is a small cage in which you put your sick or injured budgerigar to separate it from the flock to recover. The cage must be warm and humid. A heat lamp or heating pad work very well for this and at a maintained temperature of around 80 degrees F or 26.5 degrees C. Because of the heat you must ensure bird does not dehydrate and water should always be available – as well as seed. Soaked millet spray will sometimes encourage the bird to both eat and drink.
The cage needs to be away from the main aviary, as in the case of an infectious disease you want it contained. It also needs to be in a quiet environment with plenty of light during the day, and dark at night.
If you cover the cage at night make sure that it doesn’t become too hot and do not put the cage in direct sunlight, to avoid over-heating.