As the temperature improves outside, high risk infants have less of a chance of getting respiratory disease. RSV is a respiratory virus that typically causes mild to moderate cold-like symptoms, but in certain high-risk children it can cause a lung infection. Like the flu, RSV is a seasonal virus. The season start varies from one part of the country to the next, but it usually starts in the fall and continues into the spring. In some parts of the country, such as Alaska, Hawaii, and parts of Texas and Florida, for example, the length of the RSV season may be different. As the weather is improving, parents don’t have to worry as much of their babies getting RSV.