I used to have the problem when I ate things which caused a yeast reaction. I would become pale and cold. I think it was my body diverting energy to fight the sudden influx of yeast poison.
This problem went away when I started following the diet strictly.
I'm not sure if this describes your situation or not though. Do you follow the diet strictly? I suggest you think about what you ate before you experienced the chills (or at least pay attention to this in the future). You may find a common trigger.