Core Points - Sunscreen is essential for both beauty and skin barrier protection, with a focus on preventing damage from UVB and UVA rays [3] - Different types of sunscreen include physical and chemical options, each with distinct properties and suitability for various skin types [3] - SPF and PA ratings are critical indicators of sunscreen effectiveness against UVB and UVA rays, respectively [4] Group 1: Sunscreen Types and Mechanisms - Physical sunscreen includes inorganic agents like titanium dioxide and zinc oxide, which reflect UV rays and are suitable for sensitive skin [3] - Chemical sunscreen uses organic compounds that absorb UV rays, offering a lighter texture but may have stability and sensitivity issues [3] Group 2: Choosing Sunscreen Based on Activity - For outdoor activities, protective clothing and accessories are recommended, while specific SPF and PA ratings should be chosen based on exposure levels [4] - In high UV environments like beaches or mountains, higher SPF and PA ratings are advised, with waterproof options for activities involving sweat or water [4] Group 3: Special Considerations for Different Populations - Infants under 6 months should avoid sunscreen, relying on clothing and shade for protection, while older infants can use low-SPF physical sunscreens [5] - Elderly individuals and pregnant women have specific sunscreen needs, focusing on physical options and simple formulations to prevent skin issues [5] Group 4: Remedies for Sunburn - Immediate treatment for sunburn includes cold compresses and specific solutions available at pharmacies, with medical attention required for severe symptoms [5]

Group 1 - The core viewpoint emphasizes the importance of sun protection during summer due to increasing UV radiation, which can cause skin damage [1] - Experts categorize sun protection into two types: physical sun protection and the application of sunscreen [2] - Long-wave and medium-wave UV rays from sunlight can lead to skin aging, fine lines, and sunspots, making sun protection crucial, especially for those with sun allergies [4] Group 2 - For sunscreen that has not been opened, it can be used within three years of the production date if there are no signs of separation or unusual texture [6][8] - Opened sunscreen, particularly those with a shaking mechanism, should be shaken well before use, while lotion-type sunscreens should not be used if stored for more than six months [10] - Different demographics and skin types require tailored sun protection methods, with special attention needed for vulnerable groups [10] Group 3 - Special populations, such as the elderly, pregnant women, and those with sensitive skin, should prioritize physical sun protection methods like using umbrellas or hats, and choose less irritating sunscreens [11] - Infants under six months should avoid sunscreen products, relying instead on physical shade, while those over six months can use baby-specific sunscreens moderately [11] - Recommendations for sunscreen include SPF greater than 30 and PA rating of at least two pluses for regular activities, and SPF greater than 50 with PA rating of three pluses for intense sun exposure [13]