Like xmc said, when you have cold and/or brittle paint, your hopper needs to be pushing down very gently. Fragile paint can't withstand bolt clips in the stack, like warmer more durable paint can. In other words, what may work on a normal warm day of play may not work in the cold. Usually people have to much hopper tension and the paint can't bounce away to absorb impact from the bolt. The result is a cracked ball that then gets fired.
So in general for the cold or brittle paint you want to lower hopper tension.
Lower the energy behind your bolt so it strikes the ball stack gentler(lower LPR setting)
Raise your dwell so paintballs undergo less deforming when fired due to a longer slower jet of air propelling them. An over bore barrel can also help with this.
Raise your eye delay so the paint is always nicely settled before being fired.
Make sure your detents are 100% functional and clean.
Make sure your eyes are clean and working.