After accidents, in case of emergencies or if your child becomes ill outside of a doctor's office hours, you can call the emergency medical service or, in very urgent cases, contact the emergency services directly.
The most important telephone numbers that apply throughout Germany:
Rescue service: 112
Medical Emergency Service: 116117
Medical emergency service in your area: https://116117info.de/html/de
Poison emergency call Niedersachsen: 0551 - 19240
Pediatrician and Youth Medical Service in Niedersachsen: www.kinderaerzte-im-netz.de/nc/adressen/notdienste/?tx_mksnotdienst_pi1[sword]=Niedersachsen
If the child is transportable, you can also go directly to the ambulance in the hospitals.
Hospitals in Niedersachsen: http://www.arztauskunft-niedersachsen.de/arztsuche/krankenhaus.action
Even pharmacies have a night or emergency service. Current information can be found in your local newspaper.