The number one thing to do when learning how to get sweat stains out of hats is to check to see if your hat has a care label. If so, follow any instructions. If the hat doesn't say Dry Clean Only ...

Rinse the hat in warm water ... isn’t the first thing you’d think of when figuring out how to remove sweat stains, but you can tenderize away hard-to-remove stains. Before you wash that ...