Correct german would be "Stalingrad ist kalt und tut weh.", but "tun" is bad german in general, so "Stalingrad ist kalt und schmerzt" would be better.
But if one wants to preserve the "Kalt!" in the front, it would have to be "Kaltes! und schmerzhaftes Stalingrad." which translates to "Cold! and painful Stalingrad.".
Oh good lord Sir-Henri... The Nazi's bombed Stanlingrad into rubble - in fact, that was a part of the reason for the defeat - rubble = difficult terrain, better defensive positions for the russians, inability to use panzers effectively, and disruption of the infrastructure thereby denying the attackers any benefit from holding territory. 3/4 of Stalingrad was utter ruin.
The more I see it, the more saddening it becomes. Most people tend to look at the history of the Nazis for the horrible things that "particular" people did and for, of course, Hitler. But, many forget that a lot of these soldiers were just men fighting to get their country back out of the misery that had been unfairly placed upon it. That's not to say they weren't aware of the things they were doing or what was being done elsewhere, but after being in such a desperate situation after that treaty was created, it's only natural that they would be willing to do whatever it took to stop the pain (think drug addicts, people who cut themselves, etc. Anything that is clearly wrong and/or harmful to one's self and/or others).
Judging from what I read on the wiki of the man, Erich von Manstein, it seems like the artist was showing him to know that this was going to be a complete failure after days of attempting to achieve whatever the supposed objective is. Which brings up the sad part, imo, that is seeing those helmets with a single flower in front of them.
...that's just all my opinion, of course.
Cold! and hurts StalingradMarschall Erich von Manstein
Wiki link