1). In thermodynamics, Entropy is a measure of the randomness of the universe. As Hot and Cold meet, they balance each other out, increasing Entropy. When every source of energy has balanced itself out with every other source of energy, Entropy will be at its maximum. And then there will be no more changes.
2). When I was young, my family rented a house by a lake. We were living in Maine back then. It was winter, and the lake had frozen over. My parents made sure I wouldn't freeze--I was bundled in a snow jacket, snow pants, snow shoes, and another jacket (just for good measure). I waddled my tightly wrapped self out to the lake, dragging my dad out behind me. He looked on as I frolicked about, fast as my three-year-old legs could take me. Soon, we lay on the ice, watching the snow dance in the sky. Soaked and exhausted, I leaned against him as we made the trip back to the cabin. When my mom opened the door, I was embraced by the warmth of my home.
3). When Goldilocks entered the house, she saw three bowls of porridge. Goldilocks knew it was not right to take someone else’s food! But Goldilocks was very, very hungry. Surely it couldn’t hurt to take a bite? And so she took a spoonful of the first bowl of porridge.
“Ouch! This porridge is too hot!” she cried. Undeterred, she took a spoonful of the second bowl of porridge.
“Yuck! This porridge is too cold!” she spat. Yet she pressed on, taking a spoonful of the third bowl of porridge.
“Mmm! This porridge is just right!” she said. And she ate it all up!
4). In western alchemy, four humors were defined, each with a mixture of two characteristics. These characteristics were wet or dry, and hot or cold. The humors “blood” and “yellow bile” were hot, and the humors “phlegm” and “black bile” were cold. Those who had an excess of hot humors had a fiery temperament--they were happy, angry, ambitious, social, passionate, irrational. Those who had an excess of cold humors had a frosty temperament--they were depressed, calm, humble, introverted, lazy, rational. It was believed for one to be truly healthy, all of their humors must be in balance, known as “eukrasia”.
5). Ice is mist is frost is water is hail is rain is fog is rime is steam is ice.
6). That which is warm is known, familiar. Humans have huddled around fires since time immemorial. Hearths in homes, stoves in kitchens. One who is warm is kind, emotional, friendly. The day is warm. That which is cold is unknown. The vast seas and oceans. The tundras, the arctic. The vacuum of space. One who is cold is alien, calculating, distant. The night is cold. Darkness is cold. We have forever been afraid of the dark. Yet we fight it, with flames and lanterns and torches and light.