Three's a Crowd
"General Winter is almost like having a third, neutral player."
"General Winter is almost like having a third, neutral player," explains Duffy. "The Eastern Front was bitterly cold, especially the winter of '41 and '42, with temperatures reaching minus 40 degrees celsius. In those kinds of conditions exposed flesh can freeze in just a couple of minutes, literally a couple of minutes, and you had tens of thousands of soldiers dying of exposure to the cold." "Whose bright idea was it to take this shortcut?"
"Exposure" is the key word here. The longer you're moving your troops through deep snow during a blizzard, or neglect to provide shelter for them in buildings or troop transports, the shorter their battlefield life expectancy becomes. When the thermometer gauge above the squad drops, they'll be turned into a bunch of human icicles.
"This becomes a vital part of gameplay, because you can deny your enemy by destroying buildings, or by destroying his campfires, or by knocking out his troop transports," explains Duffy. "Players are going to move around the world in a very dynamic manner, reacting to weather, and bringing in the right units at the right time."
"Okay, who forgot to wake up Nikolai and tell him the fire is ready?"
Speaking of campfires, the Combat Engineer is the only unit that can deploy these pits of fire on the battlefield. As long as your troops can huddle around these blessed flames, their thermometer gauge will remain in the safe zone. When one isn't available, putting troops into cover will shield them from the wind and allow them to wait out the storm. Other units, like snipers, will be immune to the cold thanks to survival gear. That might not be perfectly realistic, but it wouldn't make much sense to force a sniper to hang out next to a smoking pit of fire. Blizzards will also affect off-map abilities, like preventing you from calling in strafing runs on enemy positions.
Rolling Down the River
The ice itself can be targeted and destroyed, meaning you could lose your troops, transports, and tanks to the icy depths.
The other layer that the cold weather introduces to CoH2 is how it directly affects the environment you're fighting in. For example, say an enemy takes out a bridge over a river. That means you'll have to find a new way to traverse the map, such as sending your army across the frozen patch of water. This also presents some dangers, since the ice itself can be targeted and destroyed, meaning you could lose your troops, transports, and tanks to the icy depths. Conversely, say you find your Russian soldiers overmatched by a Panzer IV -- you could attempt to lure it onto the ice and then shoot out the ice around it. "Maybe we shouldn't have put all of the tanks on the ice at the same time..."
But even if the ice is destroyed, it'll will freeze back over after a few minutes -- faster during blizzards. That could make braving a frozen path a high risk/reward decision when timing your attacks against enemy positions along the riverbanks. In addition, there will also be opportunities to commandeer enemy vehicles that are abandoned by enemy troops (and by "abandoned by" I mean "full of dead"). If your engineers get to it before theirs do, you can have them repair it and see how the German troops like a taste of their own Panzer.
I can't help but envision how much fun these new mechanics could be against human players. Just imagining the look on my opponent's face as he attempts to cross a frozen river, triggers some well-placed explosives, and watches his entire force drown in the hypothermic waters would be priceless. Does that make me a bad man, or just an expert tactician? Stalin would probably say the later.