Safeguarding the skin against sunburns is often the top priority for consumers when it comes to caring for their skin in the summertime. But  Number 4 is encouraging consumers to be mindful of other environmental stressors that can throw off skin’s pH and cause damage, such as chemicals in chlorine-filled swimming pools and the constant blasting of central air-conditioning that can dry-out skin and lead to itchiness and irritation.    To keep skin healthy this summer, Number 4 has launch...