Stars like Marilyn Monroe and Audrey Hepburn haven't lost their beauty or appeal over the decades, and a part of their magnetism lies in their effortless style. When it comes to Summer hair and makeup, we can all learn a lot from the iconic women who've made it seem easy to look chic no matter how hot and humid it was. Check out these 20 stars' classic warm-weather fixes for beautiful hair and great makeup when the mercury's rising.