Air temperature is an obvious stress factor and easy to measure. Since the human body can regulate its temperature by perspiration, air humidity influences the degree to which people are affected by high temperatures. Heat is better supported in dry weather conditions than in humid ones. There are a number of indices which attempt to combine air temperature and relative humidity in order to determine an apparent temperature.
MeteoSwiss uses the heat index of the American Weather Service (NOAA) in forecasting heat waves. If the values in this chart reach level 90 for 3 consecutive days, a heat warning is issued. Level 90 corresponds to an air temperature of 32°C and a relative humidity of 40%.
Although the weather has already been warm since June, the threshold level given by the heat index has not yet been attained for 3 consecutive days. So far, the temperature has not risen above 32°C during several days.
How to cope with heatwaves
Drink a lot, but beware of beverages containing alcohol, coffein, high sugar content or iced drinks.
Morning or evening are the best times to be outside.
Rooms should be aired in the morning and the sun should be kept out (closed shutters).
Stay in the shade or in air-conditioned rooms if possible.
Wear light and comfortable clothes.
People or animals should not be left waiting in closed vehicles.
Check on elderly or lonely people in your vicinity.
