By tapping that temperature, Fort Knox can keep cool on hot summer days and warm up in the dead of winter.

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"My project involved a method for treating leather so that it stayed warm to the touch in a hot environment and warm to the touch in a cool environment, " he said.

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While in cold climates, tea is used to warm up, hot tea can also be used to cool down, such as Moroccan mint tea, a brew of green tea leaves mixed with mint leaves.

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