If cold and flu are spread by a virus why does one get sick when goes out in the cold?

Going out in the cold does not directly cause the flu or a cold.

The cold weather creates conditions that make it easier for viruses to spread, but it is the viruses that cause the illness, not the cold itself.

Here's how cold weather can contribute to the spread of the flu and cold:

1. Dry Air: Cold weather often leads to dry air, which can irritate the nose and throat. When these membranes are dry, they are less effective at filtering out viruses, making it easier for them to enter the body.

2. Closer Proximity: During the winter, people tend to spend more time indoors in close proximity to others, increasing the chances of coming into contact with someone carrying a virus.

3. Increased Survival Time of Viruses: Some viruses, like the influenza virus, can survive longer on surfaces in colder temperatures. This means that if someone coughs or sneezes onto a surface, the virus can remain viable for a longer period and infect others who touch that surface.

4. Immune System Impact: Cold temperatures can have some impact on the immune system. When the body is exposed to cold temperatures, it diverts energy to maintaining core body temperature, which may temporarily reduce the effectiveness of the immune response.

It is important to note that while cold weather may create favorable conditions for the spread of certain viruses, it does not cause the illness itself. Staying warm, practicing good hygiene (like frequent handwashing), getting enough rest, and maintaining a healthy immune system through a balanced diet and moderate exercise can help reduce the risk of getting sick during the cold and flu season.