Layers....including a quality mock as the base layer. We have also used propane heaters in the dugout. You can try to keep the equipment warm, but you need to realize that the problem with composite bats below 50 degrees is NOT the bat, it is the softball.
For the 30 degrees, snowing, with 30mph winds we had to deal with the year before last here in the upper midwest:
Underarmour Cold gear then layers layers/layers
polar fleece snug hat (or at least the ear wrap version if hair is important....)
the iron-based hand-warmers (funny to see these fling all over the place while pitchers are pitching)
The Body Furnace : The Body Furnace!
Football hand muffs
Anderson bat (now that pyroflite is banned....)
etc.