Why red is so special in a cold winter morning

I remember as a child during winter mornings, waking up and rushing for school was made easier by grabbing my red sweater, which made the cold mornings warmer and brighter. Later, when I lived in the cold north, during the long dark winters, the cold month of December was brightened by the warmth of Christmas and the spirit of the Holiday Season wishing everyone a joyful time. The colour red brightening up each and every corner, from shops to homes in Christmas decors as in curtains, table lay-outs, warm, red candles to ribbons, not forgetting  the "Christmas flower, grown as pot plants, the Poinsettia's, yet another beautiful Christmas red spreading it's warmth all around. Amazing but true, this grows as a tall shrub here in the tropics in the summer and blossoms as a  bright red summer flower!!!  The precious stone ruby's red is meant to be warm too for the winter and it's thought to improve the body circulation and that is the true mystery of  the colour red in winter, gearing up your body and mind and providing all the warmth you need.