Americans are being asked to wear crimson, scarlet or apple-red… today in support of the American Heart Association’s annual Go Red for Women campaign.

National Wear Red Day is now in its 10th year. It’s aimed at raising awareness of heart disease, which is the leading killer of women.

Across the country, landmarks and buildings will be dressed in the color, starting with the Macy’s Herald Square building in New York City, which went “red” last night.