After-sun gel

After-sun gels are mostly water thickened into a gel, with aloe vera, humectants such as glycerin, sometimes panthenol or bisabolol for a soothing feel, and a preservative system. Some contain alcohol for a fast, cooling dry-down or menthol for a cold sensation. That coolness is largely evaporation and sensory effect rather than anything happening in the deeper skin.

The light texture is the appeal after a hot day: it spreads quickly over large areas and does not feel greasy on sun-warmed skin. The trade-off is that a gel alone often is not enough once skin starts to feel tight or peel, since holding water in takes emollients and occlusives — following the gel with a moisturiser does far more than gel by itself.

Menthol, alcohol and fragrance can sting or irritate compromised skin, so read the label if you burn easily or react often. Do not apply gels to blistered or broken skin, and see a doctor for extensive or blistering burns or if you feel unwell. Chilling the bottle is fine; applying anything frozen directly is not.