How do i get a cold or get ill overnight?

Caught some germs: "cold symptoms" may be from viruses and/or strep bacteria. Usually, one catches some germs from another person. The germs grow and multiply over a couple of days. Finally, the germs cause irritation and inflammation in the nose and throat areas... Causing the symptoms we call "cold symptoms". Sometimes allergy symptoms come on quickly, and can feel like cold symptoms.