For most New Yorkers in these sweltering last days of July, the problem is how to keep cool. For cocktail mavens, the question is what to drink. “Summer is the time when you want to lighten everything up — light rum instead of dark, blended whiskeys instead of single-malt, bourbon instead of rye,” a bartender at the Gramercy Tavern, Jim Meehan, said. “You want spirits that evoke summertime or the beach, as opposed to Calvados or brandy or rye or Scotch, which are more fireside sippers.”

Cocktail historian David Wondrich echoed those sentiments. “I start with one of the lighter varieties of liquor,” he said. “Then I always look for something with citrus, because you want the high acidity — we perceive that as cooling — along with some sort of fizz water, for the bubbles.”

What about all the fruity drinks that show up on beverage menus this time of year? “People like to use berries, because they’re in season,” Mr. Wondrich said. “But it’s easy for berry drinks or other fruity drinks to be cloying, and then it’s not refreshing. So you have to be careful not to make it too sweet or too thick.”

A spectacularly successful example of that ethos is available this summer at Ono (in the Hotel Ganesvoort, 18 Ninth Ave., 212-660-6766), where bartender Wenne Alton Davis has designed a wonderful rhubarb ginger cooler. “When I was growing up in the South, my mother used to make strawberry-rhubarb pie,” she said, explaining her inspiration. “So the drink has strawberry, rhubarbginger compote, mint, and white tea, and it’s topped with Prosecco.”

Ms. Davis’s concoction is refreshing, bright, well balanced, and pleasant without being sweet. An instant classic, it’s perfect for a hot summer day.

Another fine summer libation is available around the corner from Ono, at STK (26 Little W. 12th St., 646-624-2444), where bartender Shawn Sugrue is serving a berrybased drink called a Tempest Storm. “It’s a modern twist on a classic cocktail called an Aviation,” he said. “We take fresh berries and mash them up — right now we’re using blackberries, because they’re in season — and add lemon juice, maraschino liqueur, and Stoli Blueberry vodka.”

The result approaches, but doesn’t quite cross over into, toosweet territory. It’s sort of like drinking really fresh fruit juice, with a nice alcoholic kick.

Not everyone subscribes to the “lighter liquor” theory, however. One such maverick is Eben Klemm, senior manager for wine and spirits at the B.R. Guest restaurant group, whose venues include Vento, Atlantic Grill, and Isabella’s. “The spirit is often the least important thing in the seasonal equation — the seasonality comes from the mixers,” he said. “If you look at sales figures, most people don’t switch liquors just based on the calendar. But you can only get really fresh watermelon or strawberries in the summer. And I like to use a lot of teas in the summer, because they’re refreshing.”

With that in mind, Mr. Klemm has created a roster of drinks based on strawberries, cucumber water, and green tea. One of them, called Naked in the Rain, available at several of the B.R. Guest restaurants, features vodka, strawberry green tea, and foaming sour mix. In keeping with the summer theme, it looks like pink lemonade, and goes down almost as easily.

Over at the Gramercy Tavern, Mr. Meehan is featuring a drink called Corpse Reviver #9. That may sound like something out of a fraternity party, but it turns out “corpse revivers” have a long history. “They’re a whole category of drinks that were meant to be consumed in the morning, as posthangover pick-me-ups, so they’re good for a refreshing summer drink too,” he explained.

Mr. Meehan’s version, which is just as palatable in the afternoon or evening, features aquavit, limejuice, Cointreau, and Lillet, with a rinse of Sambuca. The effect is agreeably bracing, with the aquavit’s caraway and fennel notes contrasting nicely against the citrus-driven lime juice and Cointreau.

With the summer fruit season now kicking into high gear, Mr. Meehan plans to expand his offerings. “Strawberries just came in, raspberries just came in, so I’m just starting to get my hands on the local produce,” he said. “One thing I’m definitely going to do infuse some fresh peaches into cognac.”

Sampling a bartender’s creation is fine if you’re out on the town, but what if you’re staying home or entertaining friends? Many of the mixologists consulted for this article offered the same advice: Make punch.

“If I have friends coming over on a hot day, I’m going to make punch in the 17th- or 18th-century style,” Mr. Wondrich, a cocktail historian, said. “That’s basically what I do all summer. It’s usually a combination of rum and brandy with citrus juice, tea, sugar water, and nutmeg” (see accompanying recipe).

And here’s one other tip, from Mr. Klemm of B.R. Guest: “If you have friends coming over, you don’t have enough ice. Whatever you think you need, double it.”

Bombay Government Punch

2 cups of Demerara or Turbinado sugar
1 cup water plus 6 cups water
12 limes, juiced
2 750-ml bottles of pot-stilled rum or 1 bottle of rum and 1 750-ml bottle VSOP-grade cognac
Large block of ice
grated nutmeg to taste

OPTIONAL:

2 tablespoons loose black or green tea (or 6 teabags), brewed and chilled in advance

1) In a large pot, make a simple syrup by stirring sugar in 1 cup water over a low flame until the sugar has dissolved (about 5 minutes). Let this cool.

2) In a separate bowl, combine the lime juice with the simple syrup and stir. Add the rum or rum and Cognac.

3) Top off with 6 cups water or, for a more stimulating concoction, cold black or green tea.

4) Stir again and refrigerate. Half an hour before serving, add a large block of ice and grate nutmeg over the top.

Serves 20.