Americans spend more than $1 billion every year on products to stop sweat and body odor [source: Grossman]. It's big business and a big job -- the body has about 2.6 million sweat glands, and a person can produce 1 to 3 liters of sweat in just an hour in a hot climate [source: Fort Worth Star-Telegram]. To combat odor, wetness or both, you'll want to have an antiperspirant or deodorant (or a combination) in your arsenal. Antiperspirants work by temporarily plugging up your pores, making it impossible for the sweat to escape. Deodorants won't stop your sweat. Instead, they mask body odor with fragrance and by reducing the number of odor-causing bacteria on our skin.