Personalized Mantenga La Calma CDM Youth T-Shirt. Cinco De Mayo Youth T-Shirt - Heather with red hot chili pepper and KEEP CALM saying written in Spanish. Mantenga La Calma Es Cinco De Mayo. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.