Temperature affects mobs and players

Player in too cold and too hot biomes gets damaged or bad effects if he does not respond to the temperature. (ex: players without any defensive armaments takes damage and walks slower in a cold region) Mobs in hot biomes (ex: nether mobs, pandas, parrots) reduce health if they are at a cold biomes. Similarly, mobs in cold biomes (ex: white bears, stray) will die soon if they are at a hot biomes.