 As long as we know that this is manageable, number two, done, right? Pressure should not be causing any problems then. Number three is the humidity, the temperature that comes along with the weather changes. Anytime the temperature drops, our circulation slows down, our blood vessels constrict, and in relation to a lack of blood flow or a slower blood flow, there's less oxygenation, thereby protective muscle stiffness and spasms kick on.