Hydroquinone activity and hence final contrast and specific image color is affected by temperature. If you're too far out of bounds from 20C (68F), hydroquinone either goes to sleep (too cool) or get too active (too warm). Today I made comparison prints of the same negative, amidol vs 130, in each case on Bergger VC neutral tone. Unlike most papers, the difference was minor. A nice cool tone in each case, but still with subtle complex undertones. I toned them in GP1 gold chloride, to further cool the image.