Natures's conflicting agenda - sap rising/10F degrees temperature

I spotted this strange sight in yesterday's 10 degree temperature. Went out this morning, 10 degrees again to shoot these pictures.

The city composting center workers came last Friday to pick up the pile of pruned branches I set out on the curb. For some reason they thought it was a good idea to prune branches off the small maple trees lining the street to add to the pile. As soon as they did so, I noticed that some of the pruned trees were weeping a liquid from the cut branches. The temperature on Friday was in the low to mid 30's so I thought it unusual but not impossible for sap to rise in the trees. But now with high temperatures not rising to more than 20 degrees for a few days I wouldn't have thought the trees would continue to weep.

Despite the 10 degree temperature when the photos were taken, there is a drop of liquid on the tip of the ice dagger. I guess the sugar in the water acts as sort of an antifreeze.

I hate it when the workers trim trees. It's obvious that they don't have any training in tree pruning as they always use a small chain saw on even the smallest branches and leave a long stub or cut mid-branch. I had to re-prune the tree, cutting the stub back to the tree collar after they were done.