Most of Canada and parts of the United States has been gripped in a cold snap that has seen temperatures dip below -40ºC in some places and given the city of Ottawa the dubious distinction of being the coldest capital in the world.
While this snap may appear to be an aberration of a normal winter, there are suggestions that this could be a trend over the coming years. It's an unfortunate part of living in a changing world where warmer air over Greenland is causing a shift in the jet stream plunging cold Arctic air our way. We may hope that this might not happen again for years but there is a sense that this is something that could be recurrent well into the future.
While we may have little enjoyment from this forecast, in terms of germs and pests, this may actually be good news. Much like humans, bacteria, several viruses, insects such as mosquitoes, and mites all hate the cold. But while for us the freezing temperatures may mean a host of inconveniences, for these creatures, the cold is a matter of life and death.
The key to survival of any organism on earth is water; we all need it. When the temperature drops below zero, the tendency of that water to freeze makes living much harder. While many microorganisms and pests have means to survive temperatures just below that mark if the temperature drops to below -15ºC, the consequences are dire.
The process of death by the cold is actually pretty simple. Initially, the water that is not held in cells freezes, forming a nucleus of ice. As that nucleus grows, it both pushes against the cells causing damage as well as making the water inside the cells flush out in the hopes of preventing further ice crystal formation. This dehydrates the cells and eventually, they die.
For bacteria and viruses, that's the end, but for larger pests, such as insects, the ice formation causes a cascade of tissue damage and eventually a lack of blood flow. Soon, the entire body is nothing more than a large crystal of ice. It's not a pleasant way to die by any means. In the case of mosquitoes, if the cold snap is long enough, the population will be significantly reduced and the following summer will be far less problematic. Considering the troubles encountered last year with the West Nile Virus in the US and Canada, this cold is exactly what the public health officials ordered.
There are a few ways to take advantage of the cold weather to make life a little better. Putting those hard to wash bed covers out in this cold for a few hours will help to remove any dust mites and/or stinky bacteria but for something a little more resilient like a bedbug, a few days to a week may be needed.
Clothes can also be effectively cleaned by putting them out into the cold. In one dramatic example, a University of Alberta student had worn the same pair of jeans for months using only his freezer and a Ziploc bag to keep them from becoming overgrown with bacteria and their malodorous byproducts. There is one side effect, however, in that the clothes will be fairly stiff and may need a few minutes in the dryer to warm them up and loosen the fibres. Yet, this means of "cleaning" using cold weather is a nice way to take advantage of the temperatures and save on energy as well.
There is one final advantage to the cold weather: a better immune system. During the winter, the amount of sun seen is significantly lower than the summer and this could lead to reduced levels of Vitamin D, which is known to play an important role in keeping the immune system functioning normally. While supplementation is a key part of keeping Vitamin D levels up during the winter, there is nothing like the benefit of exposure to the sun when it's around to keep those levels high.
There's little doubt that these minor advantages will replace the rather antagonistic thoughts many have towards the cold. Yet with the potential for more freezing temperatures looming not only in the weeks but also the years ahead, there are really only two ways to look at what is to come. We can either get used to it or, we can find the positives and make it a little less unbearable.