“In the old days, it was more like a luxury project,” says Deo de Klerk, team lead for heating and cooling solutions at the Dutch energy firm Eneco. Today, his company’s clients increasingly ask for district cooling as well as district heating systems. Eneco has 33 heating and cooling projects under construction. In Rotterdam, Netherlands, one of the company’s installations helps to cool buildings, including apartment blocks, police offices, a theater and restaurants, using water from the River Meuse.

It’s not hard to see why cooling technologies are getting more popular. A few years ago, Nayral moved out of Paris. She remembers the heat waves. “My routine during the weekend was to go to the parks,” she says. Nayral would sit there well into the evening—reading Les Misérables, no less—waiting for her apartment to cool down. Recently, she has increasingly found herself spending time in shopping malls, where air-conditioning is plentiful, in order to make it through searing hot French summers. This year, unprecedented heat waves hit France and other countries in Europe.

The city of Paris is now desperate to help its denizens find cool refuges during spells of extreme heat. A key component of Parisian climate adaptation plans is the river-supplied cooling network, the pipes for which currently cover a distance of 100 kilometers, though this is due to expand to 245 km by 2042. While around 800 buildings are served by the network today, those in charge aim to supply 3,000 buildings by that future date.

Systems such as Paris’ do not pump river water around properties. Rather, a loop of pipework brings river water into facilities where it soaks up warmth from a separate, closed loop of water that connects to buildings. That heat transfer is possible thanks to devices called heat exchangers. When cooled water in the separate loop later arrives at buildings, more heat exchangers allow it to cool down fluid in pipes that feed air-conditioning devices in individual rooms. Essentially, heat from, say, a packed conference room or tourist-filled art gallery is gradually transferred—pipe by pipe—to a river or lake.

The efficiency of Paris’ system varies throughout the year, but even at the height of summer, when the Seine is warm, the coefficient of performance (COP)—how many kilowatt-hours of cooling energy you get for every kilowatt-hour of electricity consumed by the system—does not dip much below 4. In the winter, when offices, museums, and hospitals still require some air-conditioning, the COP can be as high as 15, much higher than conventional air-conditioning systems. “It is absolutely magnificent,” boasts Nayral.

But those summer temperatures are increasingly a concern. This summer, the Seine briefly exceeded 27 degrees Celsius (81 degrees Fahrenheit), says Nayral. How can that cool anything? The answer is chiller devices, which help to provide additional cooling for the water that circulates around buildings. Instead of blowing out hot air, those devices can expel their heat into the Seine via the river loop. The opportunity to keep doing this is narrowing, though—because Fraîcheur de Paris is not allowed to return water to the Seine at temperatures above 30 degrees Celsius, for environmental reasons. At present, that means the river can accommodate only a few additional degrees of heat on the hottest days. Future, stronger heat waves could evaporate more of that overhead.

Lenovo isn’t shy about trying new things. Last year, the PC maker teased a concept laptop with a transparent screen. Earlier this year, the ThinkBook Flip concept employed a flexible OLED display that folded over the top of the laptop lid, ready to flip up whenever you needed the extra screen space. At CES 2025, we saw a ThinkBook with a rollable OLED screen that expanded upward automatically at the touch of a button—this one is a real product you can actually buy.

Get ready for another whacky concept. At IFA 2025, the tech exhibition in Berlin, Lenovo unveiled its latest idea: the Lenovo ThinkBook VertiFlex. This is a laptop with a screen that can manually swivel from a standard horizontal orientation to vertical.

Portrait Mode

By default, the ThinkBook VertiFlex Concept looks like a normal 14-inch laptop. Look closely at the screen’s edge, however, and you’ll see a second layer jutting out; that’s the actual screen. Grab the right corner edge of the screen and push it upward, and the display will smoothly swivel up into a vertical orientation.

The back panel the screen is mounted on has a felt backing to keep everything smooth and scratch-free, and you can even prop a phone up here in this orientation. There’s a mechanism inside that manages the motion and keeps it operating smoothly. Despite this, the PC is still fairly slim at 17.9 mm, and it weighs roughly 3 pounds. (The 14-inch MacBook Pro is around 15 mm thick and weighs 3.4 pounds.)

I use a dual-screen setup with one vertical monitor next to my main ultrawide monitor at home. Having a vertical screen is a game-changer, as it’s perfect for applications that utilize more vertical space. Email is a great example, so are apps like Slack, anything to do with PDFs, and even most word processing software. But I’ve yet to change my screen orientation in the middle of a workflow.

Is your current smart lock frustrating you endlessly, like mine is? The Yale Approach Smart Lock (8/10, WIRED Review) is currently marked down to just $164 on Amazon, a healthy 32% discount on our editors’ top pick for smart locks. This sale comes at a perfect time, because I was just complaining about the fingerprint reader on mine no longer working.

The Yale Approach uses part of your existing deadbolt, which is great news for renters who don’t want to make major changes. You’ll also get to use your existing keys to unlock the deadbolt, which can save you a trip to the locksmith. There’s also a wi-fi bridge that needs a nearby plug to provide other services, but that’s not uncommon for smart locks. Our reviewer, Nena Farrell, even said it “works perfectly,” which is great news, because I have to unplug mine and plug it back in at least once a week.

Approach isn’t just a name, as this smart deadbolt’s standout feature is auto-unlock. By setting up your location in the Yale Access App, you can set the bolt to unlock as your get close to home, which our reviewer said “worked smoothly”, as long as she got far enough away from home for it to recognize her return. There’s an auto-lock, too, using timers from 10 seconds to 30 minutes.

This version of the Yale Approach includes the touchscreen keypad, which needs its own flat space to either stick or screw to. In exchange, it lets you set codes for yourself or friends, with options for time and access limits if you need to manage entry to your home more carefully. It also gives you an easy button to press to lock the deadbolt as you leave the house, and a biometric fingerprint scanner.

No matter what smart lock you buy, there’s going to be a little bit of hassle, that just comes with the territory, unfortunately. The Yale smooths out a lot of the worst parts by adapting to your existing hardware, and mostly stays out of the way afterwards. The auto-unlock feature isn’t totally unique to the Approach, but it is currently our favorite implementation. The price is normally a bit on the high side, so the discount here makes this a very appealing pickup for anyone ready to relegate their old front door lock to the garage door, like I’m about to.