Water's Thermal Properties

Water has an unusually high specific heat capacity — it takes 4.18 joules to raise one gram by one degree Celsius. This is why coastal cities have milder climates than inland areas: the ocean absorbs huge amounts of heat without changing temperature much.

Sweat cools you through water's high heat of vaporization. Turning liquid water into vapor takes about 2,260 joules per gram, pulling heat from your skin as it evaporates.