It’s not unusual for me to start a new year with a cold. My kids and their kids visit over the Christmas holidays from another part of the country and bring germs that I haven’t been exposed to yet. It’s a price I’m willing to pay for all of the grandkid cuddle time. Except it turns out that maybe it wasn’t the cuddling (and coughing and sneezing and baby drool) that did me in. Maybe it was building the snowman.

When I think of all of the years I snootily insisted from my scientifically-educated pedestal that catching a cold had nothing to do with being cold, I'll have to apologize to Mom for all those scarves I refused to wear. Now comes a Yale University study that builds on earlier research to proclaim that, Yes, after all, cold weather is to blame for us getting sick (along with the germs, of course).

You see, although there are a couple of hundred viruses that give us colds, about forty percent of the colds we get are from germs called rhinoviruses, and rhinoviruses like cooler temperatures. They can do their nasty work in a normal human body core temperature of 37C, but they multiply much more quickly at 33C. So when we go outside in the winter and breathe in air that drops the temperature of our inner nose and sinuses we’re making those rhino-bugs very happy campers.

But wait, there’s more. The new Yale study claims that, while that colder 33C is giving a boost to rhino-reproduction it’s also putting handcuffs on the very forces we’re counting on to defend us: immune-system proteins like interferon and others, which attack virus DNA to keep them from spreading, and kill body cells that have gone over to the other side. At 33C and colder, the genes that produce those proteins are depressed (just like us when we look at the thermometer) and don’t work nearly as well.

So what’s the bottom line when you factor all these things together? Breathing wintry air can make it as much as one hundred times more likely that the cold germ invasion will succeed!

I live in Canada (minus 25C early this morning), and I rarely let cold weather keep me from exercising outdoors, all in the name of good health. Boy, do I feel like a chump.

In my newest novel manuscript I predict that in coming years we’ll use a nano-shield spray treatment applied daily like sunscreen to protect us from germs. It can’t come soon enough. And it better work well in the cold.