Comment by mschuster91

Quite a bunch of stuff, the full law is here: https://www.buzer.de/EnSikuMaV.htm

Most important, no keeping open of store doors that blast people with warm air, no illuminated advertising of any kind between 2200-0600, no exterior lighting on buildings and structures that was not safety-critical (i.e. escape paths, flight safety), temperature control limitations for non-residential buildings, and swimming pools were shut down completely.