When the days warm up—it's only natural to compensate by wearing T-shirts that reveal more skin. But how often do you remember to apply sunscreen to your neckline and décolletage, too? If your answer is "not often," you're not alone. This is an area that can reveal your age even more noticeably than lines on your face. In fact, because you're likelier to remember to apply sunscreen to your face, the difference between the skin age of your face and the skin age of your chest or neck can appear jarring. The remedy is simple. When applying sunscreen to your face—remember to also apply sunscreen to your neck, chest, and any other exposed skin part.