I dont' know if it effects the results, but it does effect getting them. If my hands are cold then the blood just will not come out, I normally end up running my hands under a warm tap for 5 minutes to try and warm my fingers up enough if I have been outside (even with gloves) then come in to test.
A good technique is to swing your arms round like windmills for a few minutes this gets your blood moving :Twice I've done it when I'm cold and had 3.6 and 3.8 but then when I warm up I'm 6-7
Also bear in mind that your bg results can be raised by becoming overheated. I find my bg is very sensitive to temperature changes
It must be sensitive to cold then if it is with overheating