Which precautions can I take to protect myself from high ozone concentrations

The highest ozone concentrations are measured during the afternoon or the early evening (12am-8pm). Because the inhaled volume of air (and thus also the amount of ozone) is up to 20 times larger during physical activity, it is advised to avoid outdoors physical activity (f.e. running) between 12am and 8pm. Because the ozone concentrations indoors are significantly lower (see here), it is advised for sensitive persons to stay indoors during an ozone smog episode.