What to Wear in a Heat Wave
In a heat wave, wear loose, light fabrics like linen, cotton, and rayon, or moisture-wicking knits, in the most open fit you own. When 90F heat sits for days, fabric and fit matter most. Four outfit formulas plus shoe picks, so you get dressed fast and stop fighting the heat.
In a heat wave, the goal is simple: move air and move sweat. Wear the loosest, lightest fabrics you own, which means linen, cotton, and rayon for casual days, and moisture-wicking knits for anything active. Keep the fit relaxed so air can sit between the cloth and your skin and actually circulate. Skip heavy cotton, tight synthetics, and dark coated fabrics, because those trap heat exactly when you can least afford it.
🛒 The Heat Wave Outfit Forecast Formula
Temperature feel 90F and up, day after day, often with high humidity at night Key layer Loose woven linen, cotton, or rayon shirt, or a moisture-wicking knit tee Base layer None, or a thin wicking tee. Skip heavy undershirts that hold heat Avoid Heavy cotton, non-wicking polyester, tight fits, dark coated fabrics Footwear Canvas sneakers, leather sandals, or knit running shoes Tested in A 5-day Brooklyn heat wave, 90F to 97F, walking and commuting
Heat Wave Outfit Formulas
A heat wave is not one hot afternoon. It is days of it, with warm nights that never let your apartment cool down. Pick the formula that matches the kind of day you are about to have.
The Indoor-Outdoor Day
You are moving between a hot street and over-cooled offices, trains, or shops. A loose woven linen or rayon shirt is the answer here. It breathes on the sidewalk, and a light long-ish cut takes the edge off aggressive air conditioning so you are not shivering one minute and sweating the next. Wear it open over a thin tee or on its own with light cotton trousers or shorts.
Weatherproof Vintage Rayon Camp Shirt
Rayon drapes off the skin and stays cool at 95F, and the camp collar handles a patio or a walk to dinner without looking like gym gear.
Shop This PickThe All-Day-Outside Day
If the heat wave catches you at a cookout, a ballgame, or a long stretch on the sidewalk, fabric weight is everything. Go with the lightest weave you own and a relaxed fit, and add a brimmed hat. Light colors help a little here because they reflect more sun, but the open weave and loose cut do the heavy lifting.
The Active Day
For a hot run or any day you are sweating on purpose, switch to a moisture-wicking knit. It pulls sweat off your skin and spreads it thin so it evaporates fast, which is the only way to feel anything close to cool when it is 95F. Pair it with a lined training short and accept that you will sweat. The fabric just makes sure you are not carrying that sweat around all day.
The Quick Errands Day
Short trips in and out of the car still punish you in a heat wave because the car bakes. A cooling knit tee and a breathable short let you get in, get out, and not arrive somewhere already soaked. This is the no-thinking default for a 96F Saturday of errands.
Do pick loose, open weaves. Air movement is what actually cools you.
Do check fabric weight. Lighter cloth, measured in GSM, breathes better in sustained heat.
Do keep two or three wicking tees in rotation for back-to-back brutal days.
Don't reach for heavy cotton. It soaks up sweat and stays wet against your skin all day.
Don't wear tight synthetics that do not wick. They trap a layer of hot, damp air.
Don't count on light colors alone. Weave and weight matter more than shade.
Best Footwear for a Heat Wave
Canvas sneakers work well for casual days and city walking. The cotton upper breathes and the low profile keeps your foot from cooking. Examples include classic canvas low-tops in white or off-white. Price range: $50 to $70.
Leather sandals are the coolest option when the dress code allows them. Open construction means maximum airflow, and a real leather footbed holds up better than foam in heat. Examples include simple two-strap or fisherman styles. Price range: $60 to $120.
Knit running shoes are the move for active days. An engineered mesh or knit upper vents heat and lets sweat escape, which matters once you are moving. Examples include lightweight road-running models with a single-layer upper. Price range: $90 to $150.
Fabletics The Fundamental Short II
A light, breathable training short that pairs with any of the cooling tops above and dries fast when the heat wave has you sweating by mid-morning.
Shop This PickAvoid: rubber clogs and plastic slides for long days. They hold heat and make your feet sweat with nowhere for the moisture to go. Examples to skip: foam clogs, thick leather work boots, and anything fully closed with a rubber sole on a 95F afternoon.
Mistakes People Make
- Dressing for the afternoon, not the week. A heat wave is sustained, so the shirt that was fine for one hot day gets gross by day three. Rotate light, fast-drying pieces instead of re-wearing one heavy favorite.
- Treating all polyester the same. Cheap, non-wicking polyester is one of the worst things to wear in a heat wave because it traps damp air. Moisture-wicking knits are also polyester, but they are built to move sweat. Read the label, not just the fiber.
- Wearing it too tight. Fabric cools you by letting air sit between the cloth and your skin and then move. A skin-tight fit kills that gap. Give linen and woven shirts room to breathe.
- Forgetting the air-conditioning swing. Heat waves come with brutally cold indoor spaces. A thin loose overshirt you can throw on beats freezing in a bare tee, and it weighs nothing once you are back outside.
Why This Works
Heat leaves your body two ways in summer: through air moving across your skin and through sweat evaporating. Fabric either helps both or blocks both. Linen is one of the most breathable common fabrics, with an open weave that moves several times more air than a tight cotton twill of the same weight. That is why a linen shirt feels cool even in still air, which matters on a heat-wave night when there is no breeze at all.
Weight is the other lever. Fabric weight is measured in grams per square meter, or GSM. A summer linen or cooling knit runs around 120 to 160 GSM, while a winter flannel can hit 200 GSM or more. Lighter cloth holds less heat and dries faster. Moisture-wicking polyester knits dry roughly 50 percent faster than the same weight of cotton, which is the whole reason runners stopped wearing cotton tees decades ago. Cotton holds up to 7 percent of its weight in water before it even feels wet, and far more once you are sweating, so it sits heavy and damp through a long hot day. Match the fabric to the heat and a week in the 90s stops being something you fight from morning to night.
⭐ Jordan's Pick
32 Degrees Cool Crew T-Shirt
It feels like cotton but the cooling knit moves sweat and dries fast, so it is the tee I reach for first when the heat will not break. Cheap enough to keep a few in rotation.
Shop This PickFrequently Asked Questions
What should you wear during a heat wave? Wear the loosest, lightest fabrics you own. Linen, cotton, and rayon for casual days, and moisture-wicking knits for anything active. Keep the fit relaxed, lean toward lighter colors, and add a brimmed hat if you will be in direct sun.
What is the coolest fabric to wear in extreme heat? Linen is the coolest common natural fabric because its loose weave moves air and it dries quickly. Rayon and lightweight cotton are close behind. For active or very sweaty days, a moisture-wicking polyester knit can feel cooler because it pulls sweat off your skin fast.
Do light colors actually keep you cooler? A little. Light colors reflect more sun than dark ones, so they help in direct sunlight. But weave and weight matter more. A loose light fabric in a dark shade beats a tight white shirt in heavy cotton.
What should you avoid wearing in a heat wave? Skip heavy cotton, denim, non-wicking polyester, and anything tight or coated. They trap heat or hold sweat against your skin, which is the last thing you want when the heat does not let up for days.
Related Guides
- What to Wear in 90 Degree Weather
- What to Wear in 95 Degree Weather
- What to Wear in 80 Degree Humid Weather
- What to Wear on Humid but Cool Days
About the Author: Jordan Ellery is a weather-styling writer and former retail buyer based in New York who tests fabrics on his daily commute and weekend runs. Read more from Jordan.
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