Check the care label first
Spot test a hidden area
Mix cool water with a small amount of mild detergent
Dampen a clean cloth or soft brush with the solution
Gently scrub the sweat-stained areas
Use a cloth dampened with plain water to remove soap residue
For stubborn stains, apply a paste of baking soda and water
Let the paste sit briefly, then gently scrub and rinse
Avoid soaking the hat unless the care label allows it
Reshape the hat while damp
Air dry away from direct heat and sunlight
Repeat if needed after the hat is fully dry