Why does sunburn hurt?

Answer: UV radiation damages skin cell DNA

UV radiation damages skin cell DNA ✓ — Correct! UV radiation damages the DNA in skin cells, triggering an inflammatory response. Your body increases blood flow to the area to repair the damage, causing redness, heat, and pain. Severe sunburn can kill skin cells, leading to peeling. Always use sunscreen!

Sun exposure dehydrates the skin — Wrong. Sunburn isn't about dehydration. It's the radiation damage at the cellular level that causes inflammation and pain.

Heat from the sun burns the skin — Wrong. Sunburn isn't a heat burn—you can get sunburned on cold, cloudy days. It's the UV radiation that causes the damage.