Thanks for the replies so far. The safeguarding I'm talking about consists of things like certain taxiways being blocked off if they have no stop bars leading on to the runway, ensuring the airfield generators are running in case of a mains power failure, more regular checking of equipment tolerences such as the IRVR system.
To get these protective procedures put in place takes a bit of time, during which the weather may deteriorate further. Our manual states we must inform aircrew when the weather conditions are such that these procedures are required, but are not yet in place - so that brings about my original question - what are your procedures for such an event on a CAT 1 (I appreciate CAT 2 or 3 will be much different) approach? Can you still make the approach or is it a matter of holding for the Low Viz Procedures to be fully activated?