Mercury is ascendant. Not so much in astrological charts, but in our thermometers, on our dashboard displays and in the weather apps on our phones and tablets. The temperature is soaring, and it’s taking its toll on us and the wines we drink.

Beset by heat, wine lovers will turn to an ice-cold rosé to slake our thirst, after hydrating with water, of course. But we should also be concerned about how the summer’s blazing heat is affecting the wines we buy and store.

Wine ages gracefully in cool temperatures and dies quickly in heat. That’s why we store it in a wine cellar, or “cave” to use the French term.

Most of us don’t have underground cellars. If you are collecting wine to age for years, you might devote part of your basement to a temperature-controlled room to give your wine the best chance at longevity. If you keep only a few cases at a time, a wine fridge or cooler is fine. Otherwise, keep your wine in the coolest part of your house and use it as an excuse to keep the air conditioning low.

The real problem with summer is heat spikes. Think of how severe heat affects your energy level, then remember that wine is essentially alive. It can bake in high temperatures. We can revive with a shower, a dip in the pool or just some AC, but wine, once cooked, is gone.

A white wine that has been cooked, or subjected to high temperature spikes for even a few hours, can turn brown and oxidized. It will taste like bruised or overripe fruit. It certainly won’t taste as fresh as you expect. A red wine will taste like stewed fruit or an inner tube. It may look more brown than red and smell a bit skunky.

Here are some pointers to manage the heat stress of summer when enjoying wine:

First, when shopping for wine, put a cooler with cold packs in your car trunk. Even on an 80-degree day, a car’s interior can soar quickly to over 100 degrees. The trunk gets even hotter, because it doesn’t benefit from the air conditioning while you’re driving. But no place in your car is safe without insulation and extra cooling. If your wine shopping isn’t your last stop while running errands, think ahead and pack a cooler.

This is especially important when visiting wineries, which I certainly hope you will do. Most wineries do not have shade over their parking lots, in part because trees are habitats for insects that can spread disease to vines.

That pricey bottle you buy at your first winery stop will be prune juice by the time you finish your second tasting. Do what you can to keep it cool.

Second, be mindful of how the wine is kept in the store. With your cooler secure in the trunk of your car, take note of how the wines are kept and displayed before you buy them. Beware of wines exposed to windows and sunlight. Notice how cool the store is — air conditioning is expensive, and retailers may turn the thermostat up to save money. A noticeably cool store is a sign of a retailer serious about presenting wines at their best.

Third, don’t have wine shipped to your home. OK, you’ve enjoyed your visit to wine country in California or Oregon, and you’ve discovered some delicious wines you can’t find in stores back home. Whip out your credit card and stock up, but ask the winery to ship the wines in September or October, when the temperature is cooler. Many wineries ship UPS or FedEx, but not necessarily overnight. Even insulated in cardboard or plastic foam, wines can bake on a cross-country truck ride.

And when you aren’t home to sign for the delivery, the wines stay on the delivery truck, cooking away. If a winery is eager to ship to you in summer, beware: That may be a sign it cares more for your money than the quality of its product.

Some caveats are in order. Wines can be “cooked” before they’re even bottled, through mishandling in the vineyard or the winery. They may have been stored in hot warehouses on their way to market, sent across country in unrefrigerated trucks or across oceans in containers lacking temperature controls, only to be stacked at the port of entry for a few days waiting for clearance from U.S. Customs and Border Protection.

That’s why it’s worth paying a little more money — and a little more attention — to buy wines that have been properly handled from stores that care, and recognize that wine thrives in a cool environment.

So in the heat of summer, keep your cool — and your wine’s.

Dave McIntyre is a freelance

writer.