Fog vs Smog Whenever the humidity is high, air movement is less and temperature is low, fog is the automatic result. It occurs when water droplets are suspended in the air. Smog, on the other hand, is the combination of smoke and fog. When the level of pollutants is high in the atmosphere, the pollutant particles get mixed into the fog, thereby reducing the visibility further. The result is called smog. The smoke includes toxic emissions from vehicle pollutants, open burning of crops or industrial pollutants. Fog and smog are more common during wet or early winter. Wet winter is characterized by fall in temperature along with high humidity. Whereas, dry or late winter is characterized by absence of fog, smog and presence of chilly airy winds. Exposure to smog has known adverse health effects. Acute ill-effects may include redness of eyes, coughing or throat irritation, difficulty in breathing. Smog can trigger acute asthma attacks; it may even trigger a heart attack, stroke, arrhythmia. Children, elderly, patients with diabetes, heart and lung diseases are especially vulnerable to the adverse effects of smog and so should take special precautions to protect themselves. • Patients with asthma and chronic bronchitis should get the dose of their medicine increased during smog days. • Avoid exertion or activities like running, jogging in conditions of smog. • Avoid walking during smog hours. • Avoid going out as much as possible. • Drive slowly during smog hours. • Heart patients should stop their early morning walk during smog hours. • Remember to get flu and pneumonia vaccination.