Cold Weather: Does it kill germs or make you sick?

Will a goof freeze destroy germs?

Last week, a man told me that he was thankful for the constant freezing temperatures in Virginia because it would kill germs. I have heard this theory all of my life, but is it accurate?

When it comes to the colder months, there is contradicting information. Parents used to tell children to come inside, or they would "catch their death of cold."

Today, some people participate in cold therapy by walking barefoot on frozen ground or jumping into a barrel or tub of ice. They don't become ill but insist they receive mental and physical health benefits.

Whenever anyone was sick during the fall, my grandmother and others of her generation often said a good freeze was needed to get rid of germs. I believed cold weather destroys germs, and have welcomed freezing temperatures for this reason, but is it true? Let's look at the facts.

Studies indicate that the idea that a "good freeze" will clear the air of germs is a misconception. In reality, cold weather should be considered more of a spa day than a death sentence for bacteria and viruses.

Why the cold does not kill germs

Most germs—particularly the ones that make us sick—are incredibly resilient to low temperatures. Instead of dying, as many believe, they usually enter a state of dormancy. Still, there is something about breathing in the fresh crisp air that gives the feeling that germs are being eradicated.

In the same way your freezer preserves meat, cold temperatures preserve microbes and do not kill them. Scientists use liquid nitrogen (at temperatures around $-196$°C) to store bacteria and virus samples for decades.

Many viruses, like the flu, have a waxy "envelope" that hardens during cold weather. This coating turns into a tough gel, acting like a suit of armor that protects the virus while it travels between hosts.

How do germs survive the cold?

Bacteria are resilient. Many bacteria can form spores, which are essentially "survival pods" that protect their DNA from freezing, drying out, or even radiation.

Cold kills germs effectively only if the freezing process is slow enough to allow large ice crystals to puncture bacterial cell walls. However, most environmental cooling isn't extreme enough or consistent enough to sanitize a surface.

Why is flu season in the winter?

"Flu season" happens in the winter, not because of the germs' strength but because of human behavior and biology. There is more indoor activity with doors and windows shut tight during the colder months which keeps germs circulating.

This is why experts recommend cracking windows and doors for a few minutes each day to allow fresh air inside and to let stale air out. Also some people's immune systems are weaker during winter.

Scientists say the body can react to changes in the weather. I began walking in extreme hot and cold temperatures years ago to acclimate my body to the changes.

My family thought I was crazy to go walking in 100 degrees or freezing weather, but it works for me. I don't recommend this for others. As a rule of thumb, always check with your healthcare provider before making any changes that might affect your health.

Cold weather slows virus growth

Cold weather can slow the growth of viruses and bacteria, but does not destroy them. Studies continue to emphasize that washing hands thoroughly with hot water and soap is the best way to remain germ-free.

I felt like someone had burst my balloon when I learned that my long-held belief was not backed by science. Even so, I will accept that germs don't die in the winter cold but lie dormant.