Canyons are inherently risky. Flash floods occur without notice on sunny days. Technical skills & surrounding topography knowledge required yet does not eliminate risk.
Hot Springs Canyon is a sweet little stream in the middle of some of the knarliest desert in Arizona. You will gain a fresh appreciation for the power of water in the desert after the long drive in over rutted, starkly dry roads. The path starts at Muleshoe Ranch. This little oasis is privately owned by the Nature Conservancy, as is the first two miles of Hot Springs Canyon. The NCA grants access to hikers, but could easily revoke this access. So please be respectful of this beautiful place. I saw absolutely no litter on this entire hike, and I would love to see it stay that way.
The route is simple as can be. From the car park, drop into the stream bed and make your way downstream. There is thick vegetation along the creek even before there is surface water. In this upper part of the canyon, you may run into some trails that the Nature Conservancy has constructed for guests at the casitas. I found it easier to simply stick with the stream bed, as I was not totally sure that the trails would remain within the canyon. After approximately a mile and a half, a permanent stream enters from Bass Canyon, and the real fun begins.
The riparian vegetation is much thicker once the water enters the canyon, and the easiest path to follow is straight down the middle of the stream. Poison Ivy grows at streamside, providing further incentive to stick to the creekbed. "Canyoneering Arizona" claims that the narrow part of the canyon starts about two miles from the trailhead, but I found it to be closer to three or four. At any rate, you will soon come to a pool of water between two low rock walls. This pool is a swimmer, but you can easily bypass it by scrambling over either of the rock walls.
Shortly beyond the pool you will come to the first slot of the canyon. This slot is about thirty feet long, and is a waist deep wade. Beyond this slot the canyon again widens and stays that way for a good long stretch. But never fear, the best is yet to come. Soon, you will reach a waist deep pool that must be waded. The sweetest section of the canyon is just ahead. Here, the canyon narrows to only six feet wide, and the rock walls rise straight out of the water. This narrow section extends for at least a hundred feet, twisting and turning around corners as it goes. It is intensely beautiful. To proceed you must swim a brief distance and wade the rest.
Due to weather concerns, I did not make it past this slot, but I do plan to return to this canyon. Because it takes such a long hike to reach the cool parts of the canyon, I would agree with Tyler Williams that the best way to explore this area is as an overnight hike. This is a very cool place, the kind that deserves to be soaked up over a long period.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.