The trail starts smoothly. About 3 creek crossings. The last one is more serious. I switched to sandals and waded it though. But took awhile to swap shoes and gaiters. On the way back, walked upstream, and crossed on a pile of logs as seen on the photo. 
Then, it's a south facing slope, hot and dry. M slowed down to reduce overheating. I put half a hydration tablet in his 1/2L bottle. We all waited from time to time when we found shade. By 9am, we reached Wirtz Basin, half in cool shade.
The trail crosses the basin, onto rock fields. Partly covered with snow. Once we crossed the snow, we were higher than the trail. W who was in the lead took to the gully just right of the zigzag trail. Unstable rocks in the lower half and snow upper. All switched to crampons. I put on micro-spikes. B slipped, said she felt dizzy. M waited for her since he was the last. Later, we learned that she had heat exhaustion, and two of them turned back.
Once reached the pass, bushwhacked down ~10' and onto the trail. The traverse is good, not covered by snow. The lake was still snow covered. Saw a few tent sites by the lake outlet, and some on the ridge.
From there on was mostly snow, except the very top rocks: dry, a couple of good campsites, abundant heather and phlox. Great view all around. A couple of climbers were trying out the north cliff. The summit registry was full. I hid in the shade eating my sandwich. 
Glissade down the peak, almmost all the way to the lake junction.
We took the proper trail coming down Heedlee Pass. A lot easier. The trail was maybe 1/3 covered with snow, some loose rock. I didn't bother with spikes. At the bottom of the basin, we slide along the snow below the trail, and then rejoined the trail. Back at the TH, found M's note on the car window. Good to know that they were safe.
Now 4 of us crammed in one car. I was dropped off by I-5 exit close to home ~7:30pm. Walked the last mile home.
