Dan Schall’s knee is still pretty stiff, but he can walk all the way to the bathroom now without needing crutches. That’s a big step in the Rancho Bernardo man’s ongoing recovery from a rattlesnake bite in Yosemite National Park two weeks ago.

Schall, 49, had hiked to the top of Nevada Falls with his children and was barefoot after cooling his toes in the rushing water. But an unfortunate misstep near a baby rattlesnake led to a five-day odyssey that included two emergency helicopter rides, three days in the ICU, eight vials of antivenin and a shot of morphine to ease his throbbing leg pain. The small-business consultant said he’s grateful to be walking again after the traumatic experience, which was far more serious than he expected from such a tiny predator.

Summer is snakebite season and Schall is one of the more than 800 Californians who get bitten each year by venomous snakes. Most rattlesnake bites are not fatal — about one or two a year in California are — but they can deliver a nasty blow that can leave the victim in pain for weeks, if not months, said Dr. Richard Clark, director of the Division of Medical Toxicology at UC San Diego Health System.

Some snake experts say baby rattlesnakes can deliver a more-potent bite than an adult because they can’t control the dose they deliver, but Clark said no studies support that theory. What has been proven, he said, is that the toxicity of a snake’s venom is variable.

Dan Schall is helped to helicopter at the top of Nevada Falls in Yosemite National Park after he was bitten by a rattlesnake. — Dan Schall

“Venom changes all the time,” he said. “It will vary depending on time of day, how hot it is outside, the type of prey they’re feeding on and seasonally throughout the year. And babies can give you just as bad a bite as adults.”

Most snakebites in California occur during the spring and summer months, as well as during the Santa Ana conditions in the fall. That’s when hikers head out into the hills and when the coldblooded snakes slither out of their holes to warm themselves, Clark said.

As an avid hiker, Schall said he’s had more than a dozen encounters with rattlesnakes over the years. This is the first time the meeting ended badly.

“I know that if you leave a way out for a snake, he’ll take the exit. They’re not aggressive toward humans. They’re defensive,” Schall said.

SNAKE TIPS Spotting snakes: Never hike barefoot or in sandals. Don’t step or reach where you can’t see. Floating “sticks” in the water may be swimming rattlesnakes. Watch for snakes at the edges and doorways of buildings. Listen for the rattlesnake’s characteristic rattle warning before it strikes. Never hike alone. If bitten: Stay calm. Wash the area gently with soap and water. Remove watches, rings or items that may constrict swelling. Immobilize the affected area. Transport safely to the nearest medical facility. Don’t apply ice (it could cause a frostbite burn). Don’t apply a tourniquet (it could damage tissue). Don’t suck on the bite (it introduces bacteria to the wound). For first aid information: Call the California Poison Control 24-hour hotline at (800) 222-1222 Sources: California Department of Fish and Wildlife, California Poison Control System, UCSD Health

The bite occurred on the final day of a weeklong Yosemite vacation that Schall took with his wife, Michelle, and their children Ryan, 21, and Elyssa, 19. Michelle stayed in Yosemite Village that afternoon while her husband and the kids climbed to the top of the 6,000-foot cliff. Ryan and Elyssa were sunning themselves on a large rock shelf with about 40 other hikers and when Schall tried to join them by climbing up on the rock, the coiled snake shot out from a cranny underneath.

“As soon as I got close to where it was hiding, it lashed out at me. I felt the bite on the bottom of my right foot. I looked down and in a fraction of a second I saw the snake going back under the rock. It didn’t hurt at first,” he said.

Initially, Schall said he hoped that the bite was from a nonvenomous snake and he urged his children to stay calm and see if they could spot the snake. Ryan used a GoPro camera on a selfie stick to photograph the snake beneath the rock and another hiker identified it as a rattler, perhaps a Western diamondback. Within three minutes of the bite, the venom was already working its way into Schall’s bloodstream.

“I started getting these really funny feelings. My lips, hands and arms were tingling and then I started feeling lightheaded, dizzy and nauseous,” he said.

With a borrowed cellphone, Elyssa called 911 and within an hour, a rescue helicopter flew to the cliff top, strapped Schall to a gurney and flew him down to Yosemite Village. There he was treated with the first of two doses of antivenin, then flown to a Kaiser hospital in Fresno, where he would spend the next five days.

Schall said he remembers his foot swelling up like a balloon and his right leg becoming immobilized “like a big fat log.” When he tried walking after a few days, the pain was so intense, he needed morphine. On July 3, he was finally released and has been recuperating at home ever since.

Clark said the average snakebite victim that he sees requires hospitalization for two to three days and the patients experience massive swelling, a great deal of pain and bruising. Some lose parts of their fingers. Because the venom is absorbed by the body’s lymphatic system, it can continue to cause pain and swelling in the limbs for months.

Dan Schall's foot a few hours after a baby rattlesnake bit the underside of his right foot near the heel. Medical workers used a Sharpee pen to track the swelling on his foot. — Dan Schall

Schall said he’s still experiencing deep pain in his leg, but he can now walk up to 150 feet and is swimming again in his backyard pool. He said the experience made him appreciate his family more and in gratitude for his recovery, he’d like to do more to help his community in the future. He is also looking forward to getting back out on the trails again soon.

“One of the doctors asked me if I killed the snake that bit me and I thought that was a crazy thing to say. It was just doing what it knew to do to protect itself,” he said. “I really love hiking and if anything, I’ll do more of it now. I may be hypersensitive about looking around where I walk from now on, but next time I go to Yosemite, I’m going to go all the way up to Half Dome.”