Wind Chills are a specific type of elemental, a sub-species of air elementals. They are the cold draft in winter that makes the hair at the back of your neck rise and a shiver spread through your body. They don't visually manifest, but the air around them seems to bend and shimmer to their shape. They are native to winter, only able to be conjured during the cold season as they carry the cold fronts from place to place.
They are most active during winter storms, when the wind cuts straight through your clothing and leaves you shivering. This is often them playing, though they will never chill you too far, and will stop if told or if they see you're starting to get too cold. They are often very fun companions to have around, greeting you happily when the weather starts to turn cold or you have good air conditioning in your home.
They are adept at feeling the auras of those around them and can warn you of danger by sending a cold chill across your neck when it doesn't belong. They are excellent sentry companions, intuitive with intention and able to read people quite easily. They are also minor energy workers, ones who can help in cleansing old energies and ushering in new ones.