Unless I'm mistaken, you just don't have that good of circulation to your hands. If you do hand exercises, perhaps you can build up the amount of muscle & circulation to your hands. Get some of those strength grip things (that you squeeze to increase hand strength) and maybe that'll help. Of course, I'm not a doctor, and I may be completely wrong. Anecdotally, whenever I finish a bottled water, I'll alternate between hands trying to crush the bottle (with the cap back on). Squeezing a bathroom scale (without leaning on it), I can usually get it to between 250 and 300 pounds. I haven't seen anyone else get above 150 or so. "Kung Fu grip" is my joke. I have snowball fights with my kids - I don't need to wear gloves to keep my hands warm.