More research has been devoted towards the performance benefits of keeping the core cooler in hot conditions. Perhaps the best way to keep your engine from overheating is a constant supply of cool liquids while riding. With the Camelbak Dirt Series Podium Chill 21oz Bottle, you'll stay hydrated on your hottest off-road rides with a cool drink from start to finish with the added bonus of an integrated mud cap that keeps trail junk from contaminating the valve. Its BPA-free TruTaste polypropylene material is safer to drink from and it won't distort your drink's taste. And its double-wall construction with insulation keeps your beverage chilled twice as long as regular sports bottles. The Jet Valve cap, made of medical grade silicone, is spill-proof and self-sealing so the drink doesn't leave the bottle until you say so. The locking cap keeps the bottle from leaking while in your bag or the floorboard of your car.