Summer has many pleasures, but sweat rash is not one of them. The technical term for this common skin irritation is milaria though it also goes by heat rash and prickly heat. Milaria is caused by sweat glands being blocked and leaking sweat into the the deeper layers of the skin. This is worsened by hot and humid weather, tight clothing and the skin being exposed to dirt and grime that blocks the sweat glands and results in a rash that is unsightly and uncomfortable.
Now heat rash heals itself naturally but inflammation is bad for the skin - it's a strain on the skin's essential barrier function and it can lead to infection if it combines with bacteria. And repetitive stress compromises skin elasticity, leaves scars and discoloration. The simple fact of summer skin challenges outside of sunburn is that we are likely to spend more time outside and are as a result exposed to damaging UV radiation and pollution.
Less examined is the role of vanilla makeup combined with sweat - this is a recipe for disaster since it clogs pores faster and rather than risking merely sweat rash it breeds acne. This is ironic as sweat itself is great for your skin - right away - it eliminates toxins, boosts circulation and cools the body and skin. It might be avoided by removing makeup completely but if you live in a tropical climate skincare is a necessity to avoid looking utterly greasy.
But artificial fragrances and even thick moisturisers can all simply make summer skin a hot mess. Even ingredients like retinols that are ordinarily beneficial in the skin cannot work when the skin is inflamed and need to be given a rest. Active ingredients that lighten the skin are particular offenders as they react with the heat and result in uneven pigmentation.
If there is ever a season to embrace skincare minimalism it is the summer - a mineral sunscreen gel worn but forgotten and boosted by hats and sunglasses - a sheer layer of a genuine mineral foundation (with few ingredients preferably natural and anti-microbial) and a rose water spritz are all the skincare a hot summer day requires. More is not merely unnecessary but is counterproductive. Any potent active ingredients are best saved for overnight application to give your skin a rest as it handles the sweaty demands of the season.