Your skin may begin over-producing natural oils in winter not because you are sweating but because your skin has become dry with the cold. The dryness inversely triggers your skin to produce more natural oils i.e., sebum which results in excessively oily skin and a whole range of other issues. How can you solve this? We're so glad you asked! Here's Conatural's not-so-well-kept-secret: the best moisturizer for oily skin, "Saffron Complexion Builder".