Those two "H's" - heat and humidity - that conspire to make Baltimore summers so very special could soon be joined by a cousin: hurricane.
A not-so-holy trinity, most everyone would agree, is upon us.
The temperature soared yesterday afternoon to 93 and the humidity reached a sticky 94 percent, conspiring for a heat index of 103. Today and tomorrow look like repeats of yesterday, with chances of thunderstorms and showers.
Also, air quality was predicted to be unhealthy over the weekend for those with respiratory illnesses, according to the Maryland Department of the Environment. A network of cooling centers in Baltimore will be open for those with health problems.
Mother Nature could show some mercy by Monday night, according to the National Weather Service. A front bringing showers and thunderstorms should drop the daytime temperature to the mid- to high 80s, with a slight dip in humidity.
As if all this heat and humidity weren't enough, forecasters are also watching the Atlantic Ocean, where Tropical Storm Irene was poised to become the season's third hurricane.
Yesterday, the storm was about 650 miles southeast of Cape Hatteras, N.C., with top sustained winds of 70 mph and was expected to reach minimal hurricane standards, 74 mph, by last night.
It was moving northwest, on a course which, if unchanged, would take it to the Carolina coast by Monday or Tuesday.
But forecasters said a ridge of high pressure stood in Irene's way and seemed likely to turn the storm gradually to the north, and eventually back out to sea, before it could reach the U.S. mainland.
"But like all things in nature, we don't know exactly what path Irene will take or how she will influence our weather in the Baltimore region," said National Weather Service meteorologist Luis Rosa.
While the area wilted yesterday, some people complained, others endured and a couple of pigs received preferred treatment at the Howard County Fair.
Most could dress to beat the heat but not those young men and women at the U.S. Naval Academy who greeted their families and loved ones in Annapolis after a grueling seven-week test called Plebe Summer.
For their first exposure to freedom in a month and a half, about 1,200 mids - clad in white dress uniforms - left formation in front of Bancroft Hall and faced yet another trial - a sticky, suffocating heat blast.
"We wish there was a pool at the hotel," said plebe Carlos Campos, 20, as he met his family for Parents Weekend.
At the Howard County Fair in West Friendship, which concludes today, some members of the animal kingdom received special treatment to counter the heat.
Rabbits snuggled up to frozen water bottles, sheep lay in the breeze generated by dozens of fans and two swine enjoyed a spritzing from a spray bottle by Kathryn Knaus, 14, of Dayton.
"Pigs don't sweat," she said. "That's why pigs go in mud, they use it like sunscreen." With no mud available, the two swine, which belong to Kathryn's friend Kathleen Littleton, were enjoying the first of several planned mistings for the day.
"When it gets hot, they definitely need it," Kathryn said.
And when she gets tired of the heat, she said, "I have a pool, so I'm going to go back [home] and jump in there."
In Baltimore's Druid Hill Park, preparations were under way yesterday for today's Stone Soul Picnic.
After spending all day setting up tents for the event, Miles Clark and Frank Salerno kicked back in the shade with their feet up as they waited for a refrigerator truck to arrive, which will hold drinks and ice.
About 150,000 are expected to attend, organizers said.
Health professionals cautioned that the very young and the elderly are especially vulnerable to heat-related injuries that could be fatal.
"The precautions remain basic," said Dr. Michael Pipkin, chairman of the Department of Emergency Medicine at Franklin Square Hospital Center. "Drink plenty of water, stay in an air-conditioned environment and do everything in moderation."
Pipkin said even conditioned athletes can be felled by extreme heat and humidity, and "that's why we should pay attention to the old and young among us."
He added that dark urine could be one of the first signs of dehydration.
Pets also need attention in this weather. "Animals don't deal with heat as well as humans because they don't sweat," said Aileen Gabbey, executive director of the Maryland Society for the Prevention of Cruelty to Animals.
Gabbey said dogs should be brought inside and walked during the cooler periods of the morning and evening. Ice cubes can be a nice treat for a dog, she said.
As miserable as some folks were, suffering through the intolerable heat yesterday, Mark Kahan could make most of us count our blessings. At noon, Kahan, owner of Beltway Roofing in Reisterstown, was standing atop a roof in Catonsville where the temperature was approaching 130 degrees.
"It's downright oppressive," said Kahan. "And I was just measuring for a future job. My crews lay large rolls of rubber/asphalt roofing with blow torches. You are drenched with sweat. You must take breaks, drink loads of water, and you finish work by noon. It's brutal."
As an afterthought, he added, "but the job is nice in winter."
Sun staff writers Frank D. Roylance, Sandy Alexander, Liz F. Kay and Justin Fenton contributed to this article.
Tips for surviving the heat
Drink lots of water. Electrolyte drinks are ineffective unless you have sweated excessively. Sports drinks can be high in sugar.
Don't stop eating; eat lightly.
If you have trouble sweating, it could be the first sign of dehydration. Dark urine is another sign.
Be attentive to the elderly and very young, who are the most susceptible to excessive heat and humidity. Excessive confusion is a sign of advanced dehydration.
Salt pills are not advisable. Try a bag of pretzels.
Even athletes should take heed. Unless acclimated to the heat, a high-stress workout could be a risk. Weekend warriors not particularly fit should be especially careful or work out in a cool gym.
Source: Dr. Michael Pipkin, Franklin Square Hospital Center