Things i'd check would be:

As above - Fans are sucking in cold air from the front of the car

Is the water pump actually circulating the water
Or are the pipes DEFINATELY plumbed in correctly

Failing that - i have known that the timing being severely out causing this type of overheating.

Have you done anything to the car before this happened (ie put on a silicone hose ket) or did it just happen one day.