Figure 3: Observed relationship between daily values and percentiles of apparent temperature and numbers of deaths in Europe.

(a) Comfort temperature (purple circles; °C), and warm (red lines) and cold (blue) transfer functions (°C versus daily cases per million) for each area, as well as the average of the transfer functions for all 54 areas (black curve). Dashed straight lines correspond to the linear extrapolation of the T/M relationship inferred for events outside the range of observed temperatures. (b) Relationship between apparent temperature percentiles and daily mortality (cases per million), averaged for the 187 regions. To this aim, a percentile was assigned to each regional daily temperature, expressing its ordered position within the corresponding regional series (for example, the minimum/median/maximum value of a regional time series is assigned to percentile P0/P50/P100). Daily mortalities within each range of temperature percentiles were then averaged (circles and coloured horizontal thick lines).