Some say it’s a mistake to look back. An absent friend in anthropology would remind me that an observer’s presence changes the habitat, not always as intended and not always for the better. Both are part of the critics’ dilemma then, since both form a part of their duty. I returned to see Nixon’s Nixon with friends last Thursday at Manbites Dog Theater, a luxury my schedule rarely affords. For my troubles, I saw a markedly different performance from the work I saw the weekend prior.

Of course, no cast ever gives the same show in exactly the same way twice. Frequently, a sharp ensemble keeps making important discoveries about a work through the run of a show.

But one of the main discoveries Thursday night’s cast and audience made involved what happens to comedy when immoderate heat is applied.

Call it an unnecessary repeat of the experiments in audience duress inflicted on patrons of Sex, Drugs and Dinner in Ringside’s third-floor brimstone ballroom a few weeks ago. Though one hoped cooler heads might prevail when that show transitioned in its latter weeks to Chapel Hill’s Skylight Exchange, any possibility of that evaporated by the time Dirty South Improv proved that room an oven in its Aug. 10 stand. “Been that way for months,” the hostess behind the bar cheerily informed me as she rang up another Stewart’s Root Beer.

Granted, neither Ringside nor Skylight has defined themselves as theatrical venues. Manbites Dog has been on the scene since 1987, and Nixon’s Nixon marks the beginning of its seventh season in its Foster Street digs.

In a room whose air was becoming uncomfortably still before the actors took the stage, Nixon‘s last half-hour turned into something of an endurance rally, as patrons fanned themselves with programs in search of some relief. There clearly was a problem, well before the fourth person complained to me afterwards about the heat.

Yes, it compromised the work.

Funeral homes throughout the South used to get a lot of advertising done by donating illustrated paper fans with wooden tongue-depressor handles to country churches without air-conditioning. Omen or not, perhaps it’s part of the solution here.

At the start of a new season, it’s time for several regional theaters to ask themselves a question.

Which would they ultimately find less distracting: Pictures of Our Jesus flip-flapping back and forth in stultifying air? The ssssh of a central air system that was never modified–even after years of use–to actually keep a theater comfortable while a show is running? A series of obituaries about shows that died from heat shock?

Or elder patrons falling out in the aisles? Because when a somewhat older friend confided in me that she felt faint by the end of Nixon, I had to stop and reflect not only on a theater’s concern for its audience’s comfort, but its responsibility for their physical health as well.

Fair and final warning to all concerned: I’ve had enough. After three rotisserie theater experiences in almost as many weeks, I’m buying a digital thermometer. It’s coming with me to the theater. Please be prepared.

The preceding admonition does not apply to Mother Nature, even though her special wind, water and lighting effects–er, make that lightning–sent patrons running at the premature conclusion of Paperhand Puppet Intervention’s Wood, Stone, Fire & Bone Saturday night outdoors at the Forest Theatre. All of which made it the second show to get a second look last week when I went back Sunday–and, again, had a very different experience.

After Saturday’s run rushed from the start in an attempt to beat the rain, Sunday’s ensemble was able to relax and simply let the show breathe–which is just what it (and we) needed.

Jan Burger and Jay Hamm’s commedia dell’Arte characters, the Schnifflers, featured large magenta papier-mache heads with giant noses. They amusingly set the stage with broad physical comedy, and returned during several transitions.

But the center of Wood, Stone, Fire & Bone isn’t so much a creation story as a tale of evolution.

At the outset, Burger and director Donovan Zimmerman create a ring of beautifully designed and painted multi-story puppets representing water, air, stone, green vegetation and wood. (The large oval masks resemble religious mandalas–particularly the ones for vegetation and water.)

The number of the elementals is increased when Air gives birth to Fire, a small figure in a mask of yellow, orange and red. We then observe the fire child spending time, learning from a phalanx of animals and from his elders’ ways.

The temptation here is to describe all the different animals and entities Fire meets in exquisite detail. But surprise is an important element here, and closely wedded to delight. Instead, we’ll praise the menagerie in general, including Tori Ralston’s intriguingly designed marionettes. We’ll voice appreciation for shadow puppets that furthered the story of evolution and the chain of life.

And we’ll admit we’d never seen a bird hug an entire audience before. Was it a white heron, or the Japanese crane of peace?

Much of the evening’s magic came from the six-person band to the left of stage. Claudia Lopez and Jimmy Magoo’s wordless vocals soared over Zimmerman and Stephen Levitin’s drums and gongs and Wells Gordon’s yeoman work on upright bass. Piquant punctuation from Jil Christensen’s accordion leavened the physical comedy onstage.

Gentle humor and gentle lessons both accompanied the elements as they permitted our approach. Imaginative puppetry and music–the perfect close to a late August day. Catch it while you can.

***Pump Boys and Dinettes , Raleigh Little Theatre–Call this musical tribute to those good ol’ boys and girls down Highway 57 at that fill-em-up station and diner across the road an unapologetic one-way road trip to nostalgia, with a potent enough mix of vintage country rock, torch, show tunes and blues. But then call to make sure they’ve fixed the sound troubles that kept losing Kenny Roby’s lead guitar and burying the backing–and lead–vocals the night we saw it.

Rose Martin and Sandi Sullivan’s work on “Tips” and the Pump Boys’ “Fisherman’s Prayer” and “Catfish” were fine, along with their signature theme. In fact, the original score has only one clunker: the maudlin “Sister,” whose lyrics need a decade of estrangement to fund it, not a momentary (and thoroughly contrived) disagreement. For the rest, if you can actually hear ’em, you’ll probably head home happy. (Wednesday-Sunday, through Sept. 5. $18-$12. 821-3111.)