In case of an emergency you should call the phone number 112 to call the ambulance. In emergency cases You can also go to the local emergency service at the hospital. There is a local service if You need a doctor at the weekend, call 116117.
Poison emergency call Thüringen: 0361-730730
Medical emergency service in your area: https://116117info.de/html/de
Pediatrician and Youth Medical Service in Thüringen: https://www.kinderaerzte-im-netz.de/nc/adressen/notdienste/?tx_mksnotdienst_pi1[sword]=th%C3%BCringen
If the child is transportable, you can also go directly to the ambulance in the hospitals. Hospitals in Thüringen: https://www.deutsches-krankenhaus-verzeichnis.de/suche/Bundesland/Thueringen.html
Even pharmacies have a night or emergency service. Current information can be found in your local newspaper.