Heading to the New England tablelands sometime this week for a few days, forecast is for about 2-13deg while I am there (although where I am staying will be a few degrees cooler). Is there anything I need to know when shooting in close to zero deg weather? Any special precations required when changing lenses? I am able to leave my bag in an open shed/car hole to 'aclimatise', is that a good idea for early morning shooting?

Cheers
Terry