When you get a sunburn, it’s not your skin cells being damaged by the sun and dying, it’s your skin cells’ DNA being damaged by the sun and them killing themselves so they don’t turn into cancer. 00
The stated sunscreen SPF values are correct only if…
The stated sunscreen SPF values are correct only if 2 μL of sunscreen is applied per square cm of exposed skin. This translates into about 28 mL (1 oz) to cover the whole body of an adult male, which is much more than many people use in practice.