It was a joke about a mother, cocaine and Walmart that set the man off.

He had been sitting with a woman at the Laugh Factory in Chicago this winter, shouting enthusiastically in response to a joke about drugs when, after being needled about his relationship with the woman, he said that she was his mother.

So when Joe Kilgallon, the next comedian, took the microphone, a joke popped into his head.

“That’s healthy — cocaine with your mom on a Monday,” Mr. Kilgallon recalled quipping. “Getting some real Walmart vibes here.”

The man leaped from his chair, cursed and made a beeline for the stage, club officials and Mr. Kilgallon recalled. A security guard grabbed the man before he could climb onstage and hustled him out of the club through an emergency exit.

It wound up nothing more than a minor confrontation, the kind that comedians have had to deal with for years, given that making fun of people and mixing it up with hecklers is basically part of the job description. But a couple of recent high-profile physical attacks on comedians — Will Smith slapping Chris Rock onstage at the Oscars in March and a man tackling Dave Chappelle as he performed at the Hollywood Bowl last week — has left some comics wondering if the stage is becoming less safe, and has led some clubs and venues to take steps to beef up their security at comedy shows.

Laugh Factory officials say that as a result of the recent unrest, they have added cameras and metal detectors and increased the number of security guards at some of their locations. They have made a few additions — “This is not a U.F.C. match!” “We do not care about your political affiliation!”— to the standard monologue about two-drink minimums people hear as they walk in the door. The Uptown Comedy Corner in Atlanta last weekend hired an off-duty police officer to bolster its security, moved one of its guards closer to the stage and began using metal detecting wands to check patrons and their bags at the door. And the Hollywood Bowl said it had implemented its own “additional security measures” after the attack on Mr. Chappelle.

“When a comedian gets onstage, what is their only goal?” asked Judy Gold, the comedian and author of “Yes, I Can Say That: When They Come for the Comedians, We Are All in Trouble.” “To make you laugh. That’s it.”

“When you take the comedian’s intent out of the formula and you decide ‘I am going to take this joke the way I perceive it, instead of the way the comedian intended it,’ ” she said, “and then say ‘I didn’t like that joke, I want that person canceled or silenced or beat up,’ I mean, it’s just devastatingly sad.”

In interviews, comedy club owners and comedians themselves expressed varying degrees of concern over the recent events. While some spoke of a worrisome uptick in audience outbursts that predates the Oscars, others cautioned against conflating what happened to Mr. Rock and Mr. Chappelle and drawing overly broad conclusions.

Trevor Noah addressed the situation with comedy last week, when he warily walked out onto the stage of his Comedy Central program, “The Daily Show with Trevor Noah,” under the watchful eye of a man in a black windbreaker that said “Security” who appeared to murmur into a Secret Service-style earpiece as Mr. Noah opened the show.

Noam Dworman, the owner of the Comedy Cellar in New York, said he viewed the Smith-Rock confrontation as a highly specific “one-off” in which Mr. Smith seemed to be trying to embarrass Mr. Rock more than physically hurt him. Seeing an audience member tackling Mr. Chappelle was concerning, he said, but might be part of a broader trend.

“It just seems like violence is creeping up on us,” Mr. Dworman said, citing recent riots and protests that have turned violent. “We have a lot of people equating words with violence. And the logical extension of equating words with violence is to say that it’s reasonable to answer words with violence.”

Some comedians brushed off concern about their personal safety, noting that they are not, for the most part, big names like Mr. Rock and Mr. Chappelle. Several made clear they did not plan to soften their material. But some worried that societal forces, including the bitter debates of the Trump years and the difficulties many faced during the pandemic, may have left people increasingly on edge — and less willing to take a joke.

Jamie Masada, the owner of the Laugh Factory, said he had been counseling his comedians to take into account that some audience members have spent much of the last two years inside their apartments during a grueling pandemic. Mr. Kilgallon said he believed that after so much time alone, “people don’t know how to act in public” — whether it be in comedy clubs, bars or sporting events.

Comedy clubs have long employed bouncers and security guards to deal with the occasional patron who has been overserved, or who is heckling a tad too much. And long before Mr. Smith strode onto the Academy Awards stage to slap Mr. Rock as retribution for a joke about his wife, there have been scattered instances of people confronting comedians during their sets, or in some cases, physically assaulting them.

In the aftermath of the Oscars slap, some comics warned of the potential for copy cats. Mr. Smith was not only not removed from the Dolby Theater after hitting Mr. Rock but was given a standing ovation soon afterward when he was awarded the Oscar for best actor. (He was later banned from the Oscars for 10 years.)

“These people gave him a standing ovation and no punishment,” Ms. Gold said of Mr. Smith. “We all said there will be copycat assaults. And there was.”

The attack on Mr. Chappelle was murkier. A man carrying a weapon tackled Mr. Chappelle onstage at the Hollywood Bowl, where he was appearing as part of “Netflix Is a Joke: The Festival.” The Los Angeles city attorney charged Isaiah Lee, 23, with four misdemeanors in connection with the attack, including battery and possession of a weapon with intent to assault; Mr. Lee has pleaded not guilty.

The Los Angeles police have not released any information about Mr. Lee’s motive for the attack on Mr. Chappelle, whose comedy has provoked controversy in the past. Mr. Chappelle discussed the encounter at another comedy show in Los Angeles later that week, according to The Hollywood Reporter. Mr. Chappelle told the audience that he had spoken to Mr. Lee after the incident, and said that Mr. Lee had said he did it to draw attention to the plight of his grandmother, who had been forced out of her neighborhood by gentrification, the trade publication reported.

“More than the incident itself, it’s the reaction people are having and saying — saying this is an ongoing or repeat thing,” said Angelo Sykes, a co-owner of Uptown Comedy Corner, which stiffened its security after the attack on Mr. Chappelle. “When you hear those things it makes you say, ‘OK, we can’t take those chances. We’ve got to be on the safe side.’”

In telephone interviews last week, several comedians in Los Angeles said the attacks had been a topic of conversation between comics after shows. Ms. Gold described some of her fellow comedians as “weary and tired” and said others were “freaking out.”

Comedy, she noted, is often a work in progress. “We don’t know where the line is until we bring up our material,” she said. “The audience informs us.”

Tehran Von Ghasri, a Los Angeles-based comedian, was among those who said an increasing share of “hypersensitive” audience members seemed to be coming to shows and either inviting confrontation, “looking to be offended” — or both.

Mr. Kilgallon said social media was also to blame. He has noticed that audience members are now quick to pull out their phones if a controversial topic is being discussed or a tense moment arises. But he said that the fundamentals of comedy remained the same.

“Over the last five years, people come up to me after a show and say, ‘It’s got to be tough these days doing comedy — everyone’s so sensitive,’” Mr. Kilgallon said. “And I say, ‘No, it’s not.’ I perform in the bluest parts of the country and some of the reddest parts of the country. If you’re funny — no matter what the joke is, people laugh.”