Which condition is most likely to worsen asthma symptoms in children?

High levels of ozone outdoors are particularly known to exacerbate asthma symptoms, especially in children who may have more sensitive respiratory systems. Ozone is a powerful respiratory irritant that can lead to inflammation of the airways, making it difficult for individuals with asthma to breathe. When children are exposed to elevated ozone levels, they can experience increased coughing, wheezing, shortness of breath, and overall difficulty managing their asthma symptoms.

While other factors listed, such as indoor air pollution, playing indoors, and exposure to cold weather, can also impact asthma, they do not typically have the immediate and severe effects associated with high ozone levels. For example, indoor air pollution may contribute to asthma issues over time but may not provoke acute symptoms as rapidly as outdoor ozone exposure can. This distinction is critical when considering environmental risks for children with asthma.