The transition from warm or hot to cold, especially the change from indoors to outdoors in winter makes your muscles block up almost fully. Accordingly your movements and motions turn frantically spastic. Most of all my legs move in a spastic gait and consequently I need assistance to be able to move about. My muscles stiffen up after having done exercises in warm water (aqua jogging) while these exercises are meant to losen up the muscles. Therefore, I need more heat (water) to losen up the muscles again.