Very disappointing stay. We booked Golden Tulip in Kassel specifically because the hotel advertised air conditioning. Upon arrival, we were told that the air conditioning was not working and were given a fan instead.
The room was 41°C, which made it completely impossible to sleep. We did not sleep at all and left the hotel at 4:45 in the morning to continue our trip.
This was not worth the money at all. A hotel should not advertise air conditioning if it cannot provide it, especially in extreme heat.