Does Cold Air Kill Germs? What About Heat?

Does Cold Air Kill Germs? What About Heat?

Yes, it's that time of year again where your nose will be dripping out of control. While you're having your sneezing frenzy, ever wonder why does the flu spread in the winter? Shouldn't the freezing cold temperature kill the germs and end the flu epidemic? If cold can't kill bacteria and viruses, can heat do the job? Don't worry as we have all the answer here. Any questions involving temperature, germs, and weather will be addressed below.
Short answer
Normal cold air will not kill germs but heating will.
Long answer

Here's some scary stats about flu from CDC. 5% to 20% of the U.S. population gets the flu every year. That's 9.3 million to 49 million of illness cases since 2010. Flu results in 31.4 million outpatient visits each year and more than 200,000 hospitalizations each year. 58% of the deaths occurred in adults are age above 65. The flu costs an estimated $10.4 billion annually in medical bills. It also affects employees to miss around $17 million of workday. In 2017-2018, the flu vaccine is rated at 40% effectiveness and prevented 5.3 million illnesses.

Does Cold Air Kill Germs?

It may, but the air must be below freezing cold to kill the germs. The membranes inside the germs will break and causes it to dry off or die. The main problem is most bacteria and viruses already found their way on a host with a warm body. Our human body will provide the right temperature and nutrients for the germ to survive thus the outer cold weather does not make a big difference.

Does Heat Kill Germs?

Most germs can be killed through heat 165º F or higher so UV-light or sterilizer will work. For food-related bacteria, cooking will do the trick. You can either boil them with hot water, pasteurize or bake them with an oven. The higher the temperature, the faster the germs will be killed. Most canned food is prepared at high-temperature to ensure no germs are left in the can. There are extremophiles that can survive in extreme temperatures and conditions. Those are the rare few that we don’t encounter very often.

Why Do We Get Colds In Winter?

The reason why we always get colds and flu in winter is because of the lack of outdoor activities. We will spend more time indoor with poor air circulation surrounded by people that may be sick. For instance, shopping mall, cinema, cafes, train station will be packed with people. Germs are often passed from a person to person through cough, sneeze, or simple gestures like shaking hand, hugging. You will likely catch a cold through direct contact with a fresh airborne virus.

Another reason why colds and flu are more prevalent in winter is the lack of natural sunlight. Sunshine can kill bacteria and viruses according to many studies. As the density of airborne germs is less, our exposure rate to the microorganisms would also decrease. Bacteria and viruses tend to live longer indoors during winter as the air is less humid than outside.

From the doctor perspective, the body immune system tends to wear down in cold weather as we are running low on vitamin D (sunlight). As we breathe in cold air, our blood vessels will thicken to help retain our body heat. This causes the white blood cells to ignore the harmful viruses and we end up with bad flu like influenza.

What Temperature Kills Germs In The House

Most germs will die from 165 degrees F to 250 degrees F (121°C) within a couple of minutes. That’s the recommended temperature from food scientists to heat up meat, fish, pork before serving. Some viruses can be killed at temperatures lower than 140 degrees F (hot water). For dry heat sterilization, switch the temperature to 320 degrees F (160°C) for 2 hours or 338 degrees F (170°C) for 1 hour.

In short, hot water does not necessarily kill germs but boiling water does. The higher and longer the germs are under extreme temperature, the faster and more germs will die.

How To Avoid Getting Sick In Winter

Germs love the indoor as it is the best place for the flu to spread. So to prevent flu from spreading too much love, here are tips that will prevent you from getting the flu in winter.

  1. Vitamin D – Take 2,000-10,000 IU of vitamin D3 a week to reduce fewer colds and flu up to 70 percent.
  2. Fresh air is the best medicine – Go for a long walk instead of staying at home the whole day.
  3. Get an air purifier with UV light – Germs can stay suspended in the air for days until it is inhaled or ingested. An air purifier will trap and eliminate airborne bacteria and viruses.
  4. Stop touching yourself – Viruses often pass from hand to mouth. Avoid touching your face, nose, eyes, and mouth. Sanitize your hand as frequent as possible.
  5. Sanitize household objects – Items you touched every day like a doorknob, remote controls, keyboards, handles, and so on.
  6. Exercise regularly – At least 3 times a day for 20 minutes. It can improve the body immune system and upper respiratory tract from infections.
  7. A good night sleep – Between 6-8 hours without any interruption. A person with consistent quality sleep is 28% less likely to catch a cold.
  8. Eat protein-rich foods – With milk, eggs, fish, and greek yogurt. Yogurt is our favorite as it contains a strain of probiotics that will boost our body defense against viruses.
  9. Take flu shots – Influenza vaccines can be taken annually to protect against infection by influenza viruses.
  10. Don’t smoke or hang around with smoker – Smoking increases your chance of respiratory infections. You will be more vulnerable to seasonal cold, influenza or H1N1 (swine flu).