Why does sunscreen protect skin?

Answer: It absorbs or reflects UV rays

It cools skin temperature down — Wrong. Sunscreen doesn't work by cooling skin. It protects by blocking UV radiation through two methods: chemical sunscreens absorb UV photons and convert them to harmless heat, while physical sunscreens (zinc oxide, titanium dioxide) reflect UV rays. UV radiation damages DNA in skin cells, causing sunburn, premature aging, and skin cancer. Sunscreen prevents this UV damage.

It absorbs or reflects UV rays ✓ — Correct! Sunscreen protects through two mechanisms: (1) Chemical filters absorb UV photons and convert them to harmless heat through molecular reactions, (2) Physical filters (zinc oxide, titanium dioxide) reflect/scatter UV rays. Both prevent UV radiation from penetrating skin and damaging DNA, which causes sunburn, premature aging, and increases skin cancer risk. SPF indicates how much UVB protection—SPF 30 blocks 97% of UVB.

It moisturizes skin deeply — Wrong. While some sunscreens include moisturizers, moisturizing isn't the protection mechanism. Sunscreen works by blocking UV radiation—chemical ingredients absorb UV and convert it to heat, while physical ingredients (zinc, titanium dioxide) reflect UV. These prevent UV from penetrating skin and damaging DNA. Moisturizing is a bonus feature, not the sun protection mechanism.