The alarm goes off, and you stumble out of bed.

The house senses you stirring and wakes along with you.

The thermostat kicks the temperature up a few degrees, the window blinds slowly open. Lights blink on as you walk into a room, dimly at first, so your eyes can adjust. By the time you've reached the kitchen, the coffee is ready. You open a cupboard to reach for a mug, and the radio pops on, ready with the daily weather report.

Welcome to the "Internet of Things," an era when ordinary objects — from coffeepots and refrigerators to doorknobs and thermostats — are being transformed into high-tech devices controlled by sensors and smartphones. A future house might even run itself — with doors talking to the lights and lights talking to televisions.

The Jetsons would be jealous.

Yet as the number of "smart" devices multiply, there are serious concerns about safety and privacy — anything on the Internet could be vulnerable to hackers. Then there are the amusing questions of necessity. Do you really want an Internet-connected toothbrush that reports your teeth-cleaning habits to your dentist?

"Technology for technology's sake is interesting to a very small subset of people," said Scott Vlaminck, co-founder of SmartThings, a Minneapolis company that makes home automation kits. "For real-world use, it needs to solve real-world problems."

Cool down by phone

Jess Myers of Inver Grove Heights uses the popular Internet-connected thermostat Nest to solve a common Minnesota dilemma: climate control when coming home from a summertime weekend at the cabin.

"It used to be you'd turn the [home] thermostat up and it'd be 85 degrees in your house" when you got back, Myers said of his summertime quandary.

Now he opens his Nest app on his phone and turns down the temp as he's heading home from Up North."That alone is worth it if you can't sleep when it's hot," he said.

Nest, which also makes smart smoke alarms, made headlines in January when Google bought it for $3.2 billion. The thermostat costs $249 and promises convenience and financial savings through energy efficiency.

That appealed to Jeff Sauer of Roseville. He bought the first version of Nest and now says he has a "love-hate relationship with it." A frequent traveler, he likes the ability to control his home temperature from afar. But he said the suggested temperature settings for peak efficiency seem more appropriate for a milder climate.

"They'll scold you for [not] being energy-efficient when it's minus-18 degrees outside in Minnesota," he said, joking.

Then there was the day his Nest lost its Wi-Fi connection and turned off. After some quality time spent on the phone with tech support, the company sent him a replacement thermostat.

"I understand that a lot of this is [first-generation] stuff," Sauer said. "As part of that, you take the good and take the bad."

Thermostats are just one way to get started.

Counting up every TV, appliance and household gadget, tech research firm Gartner says there could be 26 billion smart devices by 2020. That doesn't include computers, smartphones and tablets.

"We're in a phase of a lot of experimentation," said Jonathan Gaw, research manager with IDC, specializing in connected home technology. "What we're aiming for is a system where a lot of your devices kind of act in concert, they behave together."

Smart, but secure?

If everything is connected, what happens if a thief hacks your door lock or messes with your thermostat from afar?

Proofpoint, an IT security firm, said in January that a cyberattack used 100,000 smart devices, including refrigerators and TV sets, to send malicious e-mails.

But Derek Meister, an agent with Best Buy's Geek Squad, said that common-sense security measures would protect most consumers.

"Whether it's your refrigerator or your laptop, you should be using the same security to protect both," Meister said.

His suggestions? Make sure your home network is encrypted, use strong passwords and keep software up to date.

Some big names in home security and communications, including ADT, Comcast and AT&T, have waded into the smart home craze, pitching full-service packages for customers who want the digital bells and whistles but don't want to build their own network of high-tech devices.

Chris Tiedeman of Blaine had AT&T install a home automation and security system this fall. From his phone he can control the thermostat, lights and security system. If he's not home when his parents stop by, they can text him and he unlocks the door from his smartphone or tablet.

"I haven't used a key in months," said Tiedeman, who works in public affairs and does some work on contract for AT&T.

SmartThings, with offices in Minneapolis and Washington, D.C., offers a more do-it-yourself approach through sensors, smart outlets and a central hub that syncs different smart devices so they can be controlled with one app.

Using a smartphone to command household gadgets is a novelty, but SmartThings co-founder Vlaminck said the broader vision is for homes that use sensors to respond to your every need — no controls necessary.

"With a few rules, your house can start reacting to you and doing things for you," Vlaminck said.

But even at his house, old habits die hard.

"[My wife] can reach the light switch from the couch, so me turning it on from my phone is not all that exciting in itself," he said. "The light switches have worked in our house for a long time."

Katie Humphrey • 612-673-4758