Is it okay to hike in cotton if it's hot?

No. Cotton absorbs sweat and stays damp, preventing your body from cooling itself effectively. In high heat, this leads to overheating and chafing.

Should I wear sunscreen if I'm covered in clothes?

Yes. Apply broad-spectrum SPF 50+ to your face, ears, and any exposed skin, even if you are wearing long sleeves.

Why shouldn't I wear waterproof shoes?

Waterproof shoes contain a membrane that keeps water out, but also keeps sweat in. In the Arizona summer, your feet need maximum ventilation to prevent blisters and swelling.

How to Dress for Desert Hiking in Arizona Summer Heat

Dress in loose-fitting, light-colored synthetic fabrics that cover as much skin as possible to prevent sunburn and dehydration. Avoid cotton entirely, as it holds sweat and stops the body from cooling down through evaporation.

Choose your base layer. Wear a long-sleeved, lightweight sun shirt made of UPF-rated polyester or nylon. It should feel loose against the skin to allow air to circulate; a tight fit traps heat.
Select the right pants. Wear loose, synthetic hiking pants. Avoid leggings or heavy denim. If you prefer shorts, ensure they are quick-dry, but know that long pants provide better protection against sun exposure and brush.
Protect your head and neck. Use a wide-brimmed hat with a chin strap. A 'desert hat' with a neck cape is even better to prevent sunburn on the back of your neck, which is a major source of heat gain.
Prioritize proper footwear. Wear breathable trail runners or lightweight hiking shoes with synthetic, moisture-wicking socks (merino wool is fine if it is thin). Avoid waterproof GORE-TEX liners, as they do not breathe enough for 100°F+ temperatures.
Add sun-shielding accessories. Wear a lightweight neck gaiter (buff) that can be soaked in water to cool you down, and polarized sunglasses to protect your eyes from the intense desert glare.

Is it okay to hike in cotton if it's hot?: No. Cotton absorbs sweat and stays damp, preventing your body from cooling itself effectively. In high heat, this leads to overheating and chafing.
Should I wear sunscreen if I'm covered in clothes?: Yes. Apply broad-spectrum SPF 50+ to your face, ears, and any exposed skin, even if you are wearing long sleeves.
Why shouldn't I wear waterproof shoes?: Waterproof shoes contain a membrane that keeps water out, but also keeps sweat in. In the Arizona summer, your feet need maximum ventilation to prevent blisters and swelling.