Adult swifts around 30 g or young swifts weighing just over 20 g or less are acute emergencies. Get to a bird-experienced veterinarian! Many of these "hunger artists" can only be saved - if at all - by an infusion that should be repeated after 12 hours. The infusion consists of restorative preparations (Amynin, Ringer-Lactate) and is injected subcutaneously under the skin of the swifts knee fold. These restorative preparations get the circulation going again.
About half an hour after the infusion, it is recommended to apply 1-2 drops of lukewarm black coffee to the weakened swifts beak. This awakens the spirits!
The emergency patient must absolutely be kept warm (approx. 32-35°C). Heat from below is best suited (hot water bottle or heating pad - be sure to check the temperature regularly!).
The infusion, which provides the swift with nutrients for several hours, has now bought time to obtain species-appropriate food and then begin very careful initial feeding.
Any experimenting on your own with bandages and tape, medicine from the neighbors chickens, grandmas heart drops, or universal cure-alls from the home medicine cabinet is strictly forbidden: Well-intentioned is far from well-done and has already brought many a foundling to an agonizing end.