Neil,
I started CC last March and stupidly left equioment on board and suffered damage to two wands (when there was apparently only a ground frost)
When there is a frost warning I am removing
All wands including power brush
Extraction machine
Metal Sprayers
Hoses
When 3degrees C or lower I also unload
All plastic sprayers and spotters
All liquid products,
It is a pain but be also aware there can still be freezing temperatures during the day so it may be a case of take what you need for the day and unload into a more sheltered area.
I am sure I that I have forgotten something but no doubt others will advise
Regards
Eddie