Have you ever woken up with a runny nose, sneezing, and maybe even a mild fever? Chances are you caught a common cold. This illness is caused by tiny organisms called viruses. When these viruses enter our body, they start to multiply, causing us to feel sick. But don't worry! Our body has a built-in defense system called the immune system. The immune system is like our body's superhero. It fights off the viruses, working tirelessly to make us feel better. Specialized cells, called white blood cells, start to attack these viruses, stopping them from making us sicker. Even though our bodies are strong, it's still important to prevent getting a cold. One way is by washing our hands regularly. This simple act can wash away many of the germs that cause the common cold. So next time you catch a cold, remember - your body's superhero is working hard to get you back on track. And don't forget to wash your hands!