By day 11, the sand was thoroughly soaked and ready to be cold as ice.

Before the crew could start building ice, they had to prepare a hard base on which to build the ice; the sand, having been fully soaked, could now be frozen to provide that base.

You may note the flurry of activity on the hardening surface.  You may also note the sarcasm oozing from the strokes and counters of that sentence.  Do you remember how thrilling it was to watch the sand dry?  Watching the ice freeze was only slightly more thrilling.  But it was a warm June day outside, so it was nice to spend some time in a cold arena.

When you dump a bunch of water on the floor, you’re bound to end up with plenty of humidity in the room; that consequence can be seen not just by the fog in the above photo, but also by the view through the glass shown in the below photo.

Next up will be day 12, when the floodgates opened.