Bronchiolitis and cold air

Cold air can irritate already narrowed airways, but bronchiolitis itself is caused by an infection rather than by going outside. A child may cough more in cool, dry air because sensitive airways react to the change. This does not by itself show that the illness is becoming severe.

Bronchiolitis causes swelling and mucus in the smallest breathing tubes. Cool air may make coughing or noisy breathing more noticeable, while warm indoor air can also feel uncomfortable if it is smoky or poorly ventilated. Watch the child’s effort and behaviour, not only the sound. See [Bronchiolitis](/conditions/bronchiolitis/) and [Wheezing](/symptoms/wheezing/).

Dress the child comfortably for the weather and avoid sudden exposure to very cold air if it clearly triggers coughing. Keep smoke, strong fragrances and other airway irritants away. Offer frequent fluids or milk, allow rest, and clear nasal mucus gently before feeds. Do not use steam or inhaled medicines without clinical advice; a [Child Health Consultation](/treatments/consultations-and-assessment/child-health-consultation/) can guide you.

Get urgent help if breathing is persistently difficult, the ribs pull in, there are pauses, the lips look blue or grey, or the child is hard to wake. Arrange prompt assessment if feeding falls, urine output drops, or the child is becoming more tired. A [Cough](/symptoms/cough/) or [Fever](/symptoms/fever/) that concerns you deserves clinical advice in context.

Ask whether outdoor activity is suitable today, which signs indicate airway distress, and how to support feeding. Ask whether a [Nebuliser Treatment](/treatments/acute-and-urgent-care/nebuliser-treatment/) is appropriate rather than starting one at home.