A sick bird will lose body heat very, very rapidly. If by some chance your bird is injured away from home keep the bird close to your skin under your shirt until you can create a makeshift incubator or get the bird to the vet or animal hospital. A temperature of 85 - 90 degrees Fahrenheit should be maintained for ill birds. To create a makeshift incubator, pin a heating pad to the side of the cage and cover the cage with towels or a cage cover. An infra-red or 100 watt lightbulb can be used as a heat source if no heating pad is available. Do not, however, place the bulb near the bird unshielded, or they may be burned. If your bird starts breathing rapidly, open mouth panting, or holds its wings away form its body, the bird is too hot.
An electrolyte solution like Pedialyte, Infalyte, or Lactated Ringers solution may be given orally by dropper to help prevent dehydration. If your bird is in shock, Gatorade may help revive it long enough to get to the veterinarian. This is due to the higher sodium concentration which elevates blood pressure and sugar which stimulates the bird.
Do not ever give your bird over the counter medications without expert advice. Do not wait to see
how the bird is "tomorrow", as you most likely will not like the answer. If you have more than one bird, quarantine the bird immediately!