WHEN Washington's temperatures soared above 100 recently, we drew up a contingency plan for a small dinner party we were giving. If the heat became unbearable, we would scoop up all the food and drive it over to our guests' house. After all, they have air conditioning. We don't.

Sandy and I learned our lesson last year about the soggy perils of summer entertaining soon after moving into our vintage '30s home. Oblivious to the weather, we had invited a half-dozen people over for a fairly elaborate meal on what turned out to be one of the city's most-torrid August days.

Things didn't start off too badly. We served drinks under a huge backyard shade tree, and a slight breeze there made the heat and humidity at least tolerable. But when the crowd trooped into the dining room, it didn't take us long to realize we had made a big mistake. Before the salad was finished, we all began dripping into our plates.

By the main course, the tie or two that had lasted this far came off. Handkerchiefs mopped foreheads. Water glasses drained faster than wine goblets. I could feel a small river running down my chest.

Our guests bore up under their ordeal as graciously as polite society requires, or at least they seemed to. Who knows what curses they struggled to stifle? By dessert, conversation -- even about the weather, by now a topic as touchy as religion -- had wilted.

That was one night nobody lingered at the table over coffee. As I recall, they skipped it entirely in the rush back to the cool comforts of their own homes.

If we invite guests now, we give them fair warning of what to expect. Both sets of parents have put off their visits until the fall.

Coping with summers in Washington wihtout air cinditioning calls for ingenuity.

Step out of the office after a long day's work, and the streets fry you. The bus is late. When it does show up, it's crowded, the cooling system is on the blink and nobody can budge the windows. Forty-five stifling minutes later -- clothing clinging to damp skin -- you open your front door in search of relief.Instead, you get a blast of hot air.

I have a friend who still grimaces when she recalls an un-airconditioned apartment she rented soon out to college. To escape the heat, she says, she filled the tub cold water and ice cubes and sat there with a book until the cubes melted.

A colleague who sports a pinstripe suit and neatly tightened tie at the office even on Washington's muggiest days, at home finds he must strip -- much to his sartorial chagrin -- to cutoffs, or wither.

Some people even have been known -- to show you the extent they will go to avoid a 90-degree living room -- to return to the office for a few hours, if only to read a novel.

One summer, I visited steamy India. On a tight budget, I stayed in inexpensive hotels -- none cooled by anything more than an overhead fan. The nights could be awful. So I got into the habit of seeking out quite lobby corners in the plushest -- and coolest -- hotels in town, settling down with a book and even napping until I felt the temperatures had dropped sufficiently in my own humble chambers.

An associate uses a similar tactic. He recommends going to the Smithsonian. It's free, and they're open summer evenings.

Sandy hates long deives. But one over-100 day, she -- only half in jest -- suggested we go for a ride in the country. The car, she pointed out, is air conditioned.

It's usually too hot to cook, so we eat salads and cold soups. That helps keep the weight down if a cold beer from the refrigerator doesn't tempt you.

We're both fond of corn-on-the-cob. One day we bought several ears fresh off the stalk when they're the sweetest. We hurried them home to the pot, but we couldn't bring ourselves to turn on the stove to boil water.The corn aged daily until, finally, in midweek a thundershower dropped temperatures long enough for us to cook it.

We sometimes barbeque, because that's done outdoors and doesn't heat up the kitchen. We'll usually put on a chicken or other meat that can be chopped up cold for a salad later in the week.

We eat out as often as the budget allows. A shrimp and avocado salad with a glass of house chablis isn't too stiff in a downtown cafe. Linger until the sun goes down. The house at least seems cooler when you finally get home.

When I was a kid, my parents sent us to the Saturday matinee to get out of the heat. That wasn't a bad idea. Some of the theaters are so cool, you need a sweater. For relatively inexpensive relief, we're partial to movies at the American Film Institute, at a $1.75 a ticket for members.

We have a hammock hanging on the back porch. If there's a breeze, that's the place you'll feel it. I know because I spend a lot of time there, dressed about as comfortably as decency allows.

In the spring, I tried to get our long-neglected yard into shape. But since the hot spell hit, I haven't had much itnerest in finishing the job. Instead, I find myself lying in the hammock, while the weeds -- the only life-form whose energy seems to increase with the humidity -- unto my work.

There are two theories about windows, and we've tried both. You should keep them open at night when its cooler and closed all day. Or, you should open them to the breezes all the time. Our only conclusion so far is that the house gets hot either way.

Here, to be honest, I must say that sticky nights ultimately forced us into buying a small window air conditioner for the upstairs bedroom. We began using it sparingly, but now the room has become a haven when we can no longer endure being downstairs.

The irony doesn't escape us. We moved out of a small apartment to a large house and now we are back into one room again.

Someday, I expect, we'll air condition the rest of the house. Meanwhile, our consolation, when friends complain about their $200 or more summer utility costs, is to point out our last monthly electric bill was only $19.