[1st post on this forum] Went up to Half Dome on 8-15-14 (got permit thru the March lottery - no one was checking permits, but you never know) with my daughter. 5th time for me; 2nd time for my daughter. Usually I take the John Muir trail - it's longer than the mist trail, but seems to have less energy expenditure since the steps on the mist trail are steep and usually wet, requiring more energy and focus . This time we went up the mist trail to the right of Vernal Fall to reduce the distance about 1/2 a mile because I thought there wouldn't be any mist and that the steps would be dry - this was the case. It's likely you would experience the same dryness on the mist trail for your hike (barring a snow storm or torrential downpour). From Vernal we went to Clark Point to hookup with the John Muir trail, which was only about .3 mile longer than continuing up the Mist trail to the left of Nevada Fall; the concern was the additional energy that would be expended by continuing on the steep Mist trail.
A short distance beyond Nevada Fall on the way up to Half Dome, my daughter began experiencing heat and dehydration issues. We rested, she drank water, and she drank water frequently as we slowly continued upward. I was prepared to turn around if she didn't get better soon. Within 1/2 a mile, her issues disappeared, and she exhibited a substantial amount of energy which then made it difficult for me to keep up with her (for a while). Because of our late start at Happy Isles (7am) and frequent rest stops, it was 3:30pm when we arrived at the base of the subdome. We did have headlamps and extra batteries (and still had a substantial amount of water - we started with 9 liters among the 3 of us, including my wife, who was not going to go beyond the subdome). I told my daughter that if we continue over the subdome and onto the top of Half Dome, it will be dark for some of our hike back to Happy Isles. That was ok with her. The subdome was easier than I expected, but going up the cables was challenging - I really felt gravity pushing down on me. A cloudless sky with very little wind and mild temps made for great condtions navigating the subdome and cables. We didn't feel any chill on top of half dome; we stayed in short sleeves. We only saw 2 other people on top of Half Dome, an almost creepy contrast from the many people on top during prior trips. Going down the cables and the subdome was easier and faster than I expected. Except for going up and down the cables, we used trekking poles for the entire hike. When going up the subdome, we shortened the poles because of the high rise of many of the steps.
We were in darkness starting about 1/4 mile before reaching the Vernal Fall bridge. The paved trail after the bridge is pretty smooth, and we had no issues getting down, having arrived at Happy Isles at about 9:15pm. Roundtrip distance about 16 miles.
Suggestions and notes:
Book:
One Best Hike, Yosemite's Half Dome, by Rick Deutsch. Many reviews on Amazon.
There is tasty clean cool water at the fountain at the Vernal Fall bridge.
Carry headlamps and extra batteries. You may even use the headlamps at the start of the hike if you begin by 5:30am when hiking in Sep.
Not too warm of a day, carry 3 liters of water; warm day, 4 liters. If you have a water filter, bring it for filling at the Merced River at Nevada Fall and into Little Yosemite Valley.
Shoes: hiking boots or real good trail runners. If the shoes are new or haven't been used on steep trails, try them out first on another trail. Hiking to Nevada Fall and back would be a good test, especially since you said you've never hiked anything like it (Half Dome). And another reason to do some less strenuous hikes before tackling Half Dome is to acclimate to the altitude. We hiked several days prior to going up Half Dome, and that included a hike to Mono Pass (over 10,000 feet in elevation) from the Tioga Road.
Gloves for going up and down the Half Dome cables. The gloves should have good leather or rubberized grips - don't use plain garden gloves. Also, don't rely on gloves that may have been left at the base of the cables. I brought 2 pairs of gloves: bicycle style gloves (fingerless) for using with the trekking poles to add comfort to the grip and to prevent blisters, and gloves with rubberized grips for the cables.
I like to have an energy bar during the hike, but I typically eat no more than 1/4 of the bar at a time to reduce the chance of feeling bloated.
If you feel dizzy or nauseous, rest and drink water. Perhaps eat food if you haven't done so for a while. When you start hiking again, if you feel worse, you might have altitude sickness. Then you should go back down. Do a search on altitude sickness to see the symptoms.
On the subdome and Half Dome, focus focus focus. If you want to look around, come to a complete stop before viewing the scenery.
Manisha, have fun and good luck.