The winter’s first blast of subzero weather has arrived, and along with it the associated risks of hypothermia, frostbite and even carbon monoxide poisoning from improperly vented heaters.

From the U.S. Centers for Disease Control and Prevention come these seasonal reminders:

- If you have to go outdoors, dress appropriately. Wear a hat, a scarf or knit mask to cover your face and mouth, sleeves that are snug at the wrist, mittens (they’re warmer than gloves), water-resistant coat and shoes, and several layers of loose-fitting clothing to help insulate your body.

- Don’t ignore persistent shivering. It’s a sign that your body is losing heat and that you need to return indoors.

- Learn the signs of hypothermia and frostbite and what to do about them.

- Use caution if you plan to use a wood stove, fireplace or space heater as a source of heat. They should be properly vented to the outside so they don’t leak flue gas indoors. Make sure chimneys and flues are cleaned periodically. Do not place a space heater near anything that might catch fire, such as drapery, furniture or bedding. Charcoal grills produce carbon monoxide and should not be used indoors or in a poorly ventilated garage.

Who’s most at risk of hypothermia: infants and the elderly.

Because infants lose body heat more rapidly than adults, they should not be allowed to sleep in a cold room. Provide warm clothing and a blanket for babies and try to maintain a warm indoor air temperature. If the power is out or no heat is available, make arrangements to stay somewhere else.

Older adults often produce less body heat because their metabolism is slower and they’re less physically active. Older persons should check their thermostat frequently during very cold weather to ensure their home is adequately heated.

Hypothermia also can occur among people who are homeless, children who are left unattended, individuals who are mentally ill, individuals under the influence of alcohol, and people such as hikers or hunters who spend long periods of time outdoors.

Let’s say you’re an employer. You’re watching the cost of health insurance go up and up and up, threatening to take an ever-bigger chunk of your budget.

You wonder: Is there something you can do to reverse the trend?

Why, yes. You can start asking your employees to do more to stay well. You can urge them to stop smoking, cut back on the soda and fast food, and join a fitness center. To sweeten the deal, you can even provide some financial incentives: extra cash for employees who make lifestyle changes. And if you really want to get tough, you can start pressuring employees to sign up for a wellness program – and penalize them if they don’t.

Some corporate employers in Minnesota are doing just that, the Star Tribune of Minneapolis reported Sunday in "Whose life is it anyway?"

At a growing number of workplaces, employees are paying a price for refusing to take part in wellness programs. Some face hundreds of dollars a year in higher costs for health insurance. Some are missing out on cash and gifts used to reward their colleagues – not for their work, but for the way they eat, exercise and conduct their lives.

For some employees, it can be just the motivation they need. But the Star Tribune asks: Are employers crossing the line?

"When you have your employer kind of dictating how to live your life, it’s kind of a scary thing," said Shawn Gertken, 35, a government worker in Wabasha County. "Where does it all end? Pretty soon they’re going to be after you if you choose to ride a motorcycle after work."

This is not easy territory for employers to negotiate. Not all workers will appreciate what can be perceived as paternalism or coercion. Some may simply have too much going on in their lives to tackle a lifestyle makeover; others may be willing to try it but fear being penalized if they can’t meet the targets.

And how far can – or should - employers go? Should they stay focused on weight and cholesterol and blood pressure, and the twin bogeymen of obesity and diabetes? Or are there other measures that also are important to people’s health – for instance, seat belt use or alcohol consumption? What about high stress levels, anxiety and depression?

It’s high time, to be sure, for employers to start putting their money where their mouth is. It’s not enough anymore for them to wring their hands about the high cost of health insurance; they also have to be willing to do something about it.

It’s not at all clear, however, what "doing something about it" should entail.

What do you think? If your employer offered a health assessment, would you take it? Do you support more aggressive action by employers to encourage their workers to be healthy? Or do you think this is an intrusion into people’s lives? Start the discussion in the comments section below.

And here’s some final food for thought: The five most prescribed drugs in the United States, according to RxList, are Lipitor, for treating high cholesterol; Singulair, for asthma; Lexapro, an antidepressant; Nexium, for treating heartburn; and Synthroid, for treatment of hypothyroidism.

An international group of researchers has identified six new genetic variants associated with body mass index in children and adults.

The study, published online Sunday in the journal Nature Genetics, adds to the evidence that weight is not solely the result of lifestyle, but rather is determined and regulated by a complex interaction of mechanisms – many of them genetic – that aren’t yet entirely understood.

The researchers found that the effect of each individual genetic variant was modest. They estimated that the 1 percent of people harboring the most obesity-causing variants will likely be an average of 10 pounds heavier than the 1 percent of individuals with the fewest variants, and 4 pounds heavier than a typical person.

The authors said their findings have uncovered only a small fraction of what are probably hundreds of regions in the human genome that may make minor contributions to obesity.

The research team tested and compared BMI data and genetic information from more than 32,000 individuals of European ancestry pooled from 15 genome-wide association studies that identified 35 genetic variants. These genetic variants were further tested for validation in more than 50,000 additional individuals, also of European ancestry.

Genetic variants in six genes were shown to be strongly associated with BMI. Four of the genetic variants were found to be associated with both adult and childhood obesity.

All six of the genetic variants were found to be activated in the central nervous system, specifically the brain and hypothalamus. Prior studies have demonstrated the role of the central nervous system in body weight regulation, including on appetite, energy expenditure and other behavioral aspects.

The results are consistent with family and twin studies which suggest genetic factors may account for as much as 40 to 70 percent of BMI variation in the general population.