Stepping from the dripping Ecuadoran rain forest into a sun looming like a blister in the sky, I thought, "This is it. This is the moment that will put Washington, D.C., summers to shame." I stepped into the sun's direct rays, daring the heat to take me.

I had traveled to eastern Ecuador--specifically to the Cuyabeno Reserve, which is located in a part of the Amazon jungle bisected by the equator--to prove that D.C.'s sticky summers were nothing compared with the pure, unrelenting heat here at the middle of the world. "Let them whine back home about Heat Advisories, Code Red and their darling little Heat Index," I sneered. "I am here to have my flesh seared by the legendary equatorial sun." I expected--heck, I wanted--temperatures as high as a genius IQ and air as thick as phlegm, an asphyxiating swelter that would reduce daytime movement to a slothlike crawl and nighttime activity to tossing in sweat-soaked sheets, muttering incoherently through cracked lips, begging for relief. I wanted to return to Washington with stories about real heat, not this lightweight Americano knockoff.

And so, standing less than one latitudinal degree south of the equator, poised in the cross hairs of the mid-day sun, I felt . . . kind of hot. Sure, visually speaking, the sun loomed larger than I remembered it above Dupont Circle, and it darkened my unprotected skin with all deliberate speed.

But, well . . . it just wasn't that bad. I'd felt worse. In fact, only days prior to my trip, during an early-June heat wave in Washington, I had sweated away workdays in my un-air-conditioned home office, listening to the defeated oscillation of an overmatched fan, the allegro panting of my dog and the pathetic predictability of local TV and radio stations as they wheeled out their extreme-heat behavior tips and warned us to not go outside unless we had to. That was much worse than this.

Although I didn't record the exact temperature at that moment, the heat during my visit was frankly unimpressive. Most days the Ecuadoran sol delivered temperatures in the low- to mid-eighties. My first day in the jungle it didn't even hit 90, yet that very day, back in Washington, it hit 91. D.C.'s average daily high for June is around 85, a good five degrees hotter than the rain forest's published highs; ditto the numbers for July and August. Even at the extremes, D.C. heat whips Ecuador's hind end: The record temperatures for Nuevo Rocafuerte, Ecuador (the weather station closest to my jungle explorations), is 95. Our record highs are 101 in June, 104 in July, 103 in August. True, jungle humidity some days hovered above 90 percent. But during some summers Washington is like that for weeks on end.

Absent from the Ecuadoran climate was Washington's distinctive Web of Death--that suffocating sheet of humid atmosphere that whacks Washingtonians across the chin like a sweat-soaked T-shirt as they step outside on the bloodiest Code Red days. In the jungle I could look across the tea-colored Cuyabeno River and see trees and birds with springlike clarity, easily discerning color and definition. No haze! The simple act of standing around didn't make my skin ooze perspiration, as it often did at home. And, here by the equator, I could breathe--deep breaths, filling my lungs repeatedly and easily, the air carrying none of the heavy malignancy I'd come to expect each August in our capital city.

Yes, I'd traveled 5,500 miles--and spent $1,200 of the company's money, if you must know--to determine this sad but simple fact: Washington summers are worse than the ones in the equatorial rain forest.

I could try to explain all the science behind this, as the good folks at the Weather Channel did with me, with admirable patience and detail. But I'll just give you the short version: Due to the Earth's girth at its waistline, and to the ever-shifting polar tilt of the planet in relation to the sun, the tropics--that's the wide middle zone that lies between latitudes 23.5 north and 23.5 south, with the equator as its belt line--are indeed bombarded constantly by solar radiation, a k a sunshine. As the nether parts of the planet tilt away from the sun during their winters, and toward it in summers, the middle of the planet stays pretty much exposed to the giant flaming ball of gas year-round.

But, alas, as my experience proved, the warmth doesn't just stay put. It is air-mailed north and south by weather systems seeking some sort of global balance. Meanwhile, the tropics get far more rain than elsewhere, further regulating air temperatures in the middle zone. Consequently, equatorial temperatures tend to peak in the mid-nineties, well short of the century mark.

So why is D.C.--considerably closer to, say, Nome than Quito is--such a hot spot? Location, location, location. In a typical summer setup, a massive system known as a Bermuda High parks over much of the eastern United States--from west of the Appalachian Mountains to slightly offshore, sometimes extending as far south as Florida. These systems spin clockwise, allowing them to snag moist tropical air from points south, wrap it around and transfer it to D.C., like a hot, damp obscene gesture, from the west or southwest. To worsen matters, these systems sweep air off the Appalachians and toward the coast, compressing and heating up that air, merging it with the tropical humidity riding the Bermuda High.

The resulting meteorological sludge--seasoned with an active layer of baked auto exhaust and air pollution--can't help but smother low-lying cities such as D.C. The compression effect "makes areas east of the mountains much warmer than they would be if the mountains weren't there at all," says Colin Marquis, senior meteorologist at the Weather Channel. Worse, D.C. lacks the coastal sea breezes that can bring relief to, say, New York or Boston. The short of it: If you think a D.C. summer is the worst you've ever suffered, you're probably right.

Of the other seven people on my five-day Ecuadoran jungle tour, six reside safely above the 45th parallel, considerably north of Washington (at Latitude 39 north): British natives Wendy and Kathryn; a Swiss couple, Diana and Markus; and Swedish newlyweds Philip and Christine, who live at Latitude 58. So these people thought Ecuador was--and this is a quote--"really hot"! They would lather on sunscreen, even in the shade, and fan themselves while seated beneath jungle canopies.

Generally I am loathe to spoil other people's harmless fantasies, but this time I couldn't help myself.

"Sometimes in D.C., the haze is so thick you can barely see across the street," I'd tell them, like a weary British soldier reminiscing about his days in Burma. "Just toweling off after a cold shower makes you sweat again."

The group would eye me blankly and process my commentary before one of them invariably asked, "Washington. Isn't that a dangerous city? I mean, in terms of crime?"

Our guide, Fabian, a rotund, good-natured and excitable Ecuadoran who had never been to Washington, seemed to think it was hot enough, judging by the patina of sweat that covered his face day and night and by the frequency with which he threw his ursine mass into the river to cool off. Almost as much as the environment itself, Fabian's ebullience made the trip. Because we all spoke English, he conducted matters in his thickly Hispanicized version of the language. Hushing us excitedly with an ear cocked to the morass of foliage, he would soon point out darting or fluttering figures and exclaim in a wild whisper, "We are seeing red howler monkeys! Do you know how lucky we are?" Or, "Ooohhh! It is the black-headed Parrot. Very rare! We are being so lucky today! Que suerte!"

When we arrived by motorized canoe at our Cuyabeno camp (nice breeze!), an hour upstream from the Cuyabeno's confluence with the milky-beige Aguarico River, Fabian declared the water level almost as high as he'd seen it in six years. "Our hikes," he promised, "will be wet."

The camp consisted of a listing dock and three raised, open-air thatch structures--a latrine, a staff hut and a 35-foot square, wall-less platform that served as our dining room, kitchen, sleeping quarters and community center, all tucked stealthily into a jungle clearing. The high thatch roof and ample tree cover diffused the sun's punch even as the temps approached 90. At least psychologically, the mere presence of the cool, swift river further dispelled any horrific visions of death by swelter.

The same factors that govern tropical heat year-round also conspire to minimize temperature variation between day and night, so our sleeping conditions--seventies and sticky--were thus acceptable, if by no means ideal. At least we benefited fully from any breezes that rose from the river, since we snoozed on thin pads atop a wood-slat floor, with only thin mosquito netting draped between us and the buzz of the forest.

When it came time to hike I was happy to have the knee-high rubber boots that the tour company had provided; they seemed the perfect complement to my high-octane bug repellent and long canvas pants to shield me from what lurked in this forest, one of the most diverse plant and insect lairs on the planet. (Ecuador contains a high percentage of the world's biodiversity "hot spots," areas with an incredible wealth of plant and animal species that are threatened by human encroachment. In Ecuador's case, this threat is mainly in the form of petroleum exploration, drilling and transport.)

Leaving camp, we set off on a thin muddy trail to learn exactly what Fabian meant by "wet."

Within three steps the water was over our boot tops, and 10 steps later it was waist deep, drawing shrieks from the Brits and questions from the rest of us about exactly what we were in for.

The answer came momentarily, when we saw Fabian, arms to the sky, wading through water that reached his chin. Against better judgment we followed, ducklings in a row, trying to avoid the roots and forest debris that littered the path, five feet below the water surface. And strangely, after all my musings on sun and heat, I felt cool--almost chilly--once we were engulfed in the wet, clammy forest.

At the headwaters of the Amazon River, the Cuyabeno jungle occupies a swath of relatively flat land that floods quickly when rivers rise. Such floods, not at all uncommon, bring to the forest all the river's life--fish, leeches, caiman alligators--giving the hiker more than enough to worry about, especially since the hue of the Cuyabeno waters makes it impossible to see more than three inches below the surface. More notorious creatures, such as piranha, caimans and snakes, tend to avoid humans, but the leeches and insects do not, making aquatic hiking extremely suspenseful. Plus, the wonder of a rain forest lies primarily in small things--a pink champagne-glass mushroom, a gray armored millipede, a golf ball-size orange spider--and peering into the green blur for such sights makes walking through the water a hilarious, treacherous exercise.

When one of us fell--a distressingly common occurrence--we had to resist grabbing the nearest plant for support, lest it be hostile, like the palm branch outfitted with urchinlike spines, or a tree hosting a colony of Conga ants, inch-long mercenaries whose bite will send a person into a three-day, 104-degree fever.

Against this backdrop Fabian trudged merrily on, perking up at the call of a monkey or rarely seen bird, pointing out the vast wealth of pharmaceutical applications among the flora and leading us across submerged, single-log bridges that would have been challenge enough if dry and visible. Through it all--deep water and dry ground, dense brush and sunny clearings--he perspired profusely, as if to prove how hot his homeland was.

And he even found us snacks, teaching us how to eat the aptly-named lemon ants (dab them off of the Lemon Ant Tree, of course) and presenting me with a live beetle larvae. I gobbled it without hesitation--an indulgence I cannot, unfortunately, explain away as a result of a soft-boiled brain stem. I still wasn't all that hot.

Abandoning hope of finding extraterrestrial heat on my jungle mission (note to self: next year, the Sahara? Death Valley?) on my final day I commissioned a guide and his four-wheel-drive Jeep to take me up the Cayambe volcano, an 18,938-foot (now dormant) peak that lifts the equator to 15,046 feet, the line's highest pass on the planet. Any place that had at some point managed to spew molten lava, I guessed, was at least a worthy nostalgic must-see for someone determined to explore the variations of equatorial heat.

Lurching up a relentlessly steep cobblestone road through a centuries-old Indian village, we could see flashes of the mountainside through swirling clouds. Soon the earthen huts ceded to lush, mossy tundra.

Where the road ended--at elevation 15,000 feet--the air was thin and windy, the temperature in the thirties. Hiking up a glacial snow field and laboring for each high-altitude breath, I felt a sting on my face.

Back home, it was sunny, humid and in the nineties. Here in the midst of the equatorial summer, perched near the summit of a great volcano, I realized the remarkable truth: It was snowing.

American and Continental airlines fly regularly to Quito, Ecuador, from Reagan National and Baltimore-Washington International airports, for around $1,000 round trip during high season. You can usually find a better deal through a consolidator that specializes in Latin America, such as Monica Travel (301-294-1166), Travel Discounters (301-590-0040) or D-FW Tours (1-800-527-2589). The Ecuador Ministry of Tourism is on the Internet at /ingles/index.html. The U.S. State Department warned in a July 13 public announcement that labor disputes in the country have disrupted transportation and caused other problems, such as food and fuel shortages in some areas. That announcement and the consular information sheet on the country is available at http://travel.state .gov/ecuador .html.

John Briley last went kayaking in the Gulf of California for the Travel provided by author