Increasing the heat in the shop will cause amount of moisture in the air to rise, warm air holds more moisture. So if you heat it it will absorb moisture and when it cools it will condense somewhere. Cool tool steel is always a good place for this to happen. So yes rusting is likely to occure more readilly with a shop that has temp fluctuations. A light spray with wd-40 or like product will help. I have known guys who have put gun blueing on the table saw table with good effect. Any moisture barrier will work, not sure about the talc though.