Now that summer is firmly in the rearview mirror, you might be tempted to retire your bottles of half-used sunscreen to the far back corner of the vanity cabinet. But do not take crisp weather as a sign to ease up on your SPF usage: UV rays are still very much present even on a cold, overcast day, and they will still wreak havoc on your skin. This is especially true when it’s snowing since light reflects off white surfaces, making areas like the back of your neck or underneath your chin susceptible.