This is my first year working at a truly business casual office and I have realized that I lack ideas for warm weather work wear. Apparently my office gets a bit chilly in summer with the A/C so that's a factor. What are your go-to fab outfits for warm weather workdays? Pics would be appreciated!

Note: Business Casual at my office (which leans towards the traditional- I actually saw someone wearing a twin set the other day) means no denim, no shorts, skirts hit the knees, and no exposed shoulders. Printed t-shirts are also discouraged.