  This paper discusses some aspects referring to the characterization and
modelling of the resilience of distribution systems in the presence of heat
waves. The aim is to identify the specific features that can lead to more
detailed modelling of the impact of heat waves on the failures that happen in
distribution systems. In particular, with heat waves there are differences
between the cumulative distribution function of the time to failure in
practical cases and in the theoretical reference used for reliability analysis.
These differences may be considered to refine the resilience models due to heat
waves. Examples taken from real cases are illustrated and commented.
