Examples of Heat Health Warning Systems: Lisbon’s ÍCARO’s Surveillance System, Summer of 2003

Abstract

During the summer of 2003 Portugal was under unusual heat stress, particularly in the period from 27th July to 15th August, when almost all Portuguese districts had weekly maximum temperatures above 32 °C.

In Portugal an operational Heat Health Warning System has existed since the summer of 1999. This system is based on meteorological data and gives three days advanced heat wave predictions. This 2003 summer had several unusual heat periods that were extremely well predicted.

This article aims at presenting the Heat Health Warning System, detailing its background, methods and its five years experience. Beyond that a particular review of the summer of 2003 is done.

The 2003 summer July–August 17 day heat wave seems to have generated about 2200 excess deaths. When age, sex and district population adjustments are made the excess mortality is evaluated at 1953 heat related deceased.

Heat related mortality affected mainly elder and female individuals.

The surveillance partners had difficulties in conveying out messages to the population, using the media, late in the heat stress period.

Our 2003 summer experience lead to the conclusion that active ways must be sought to convey information to the population, when such a silent disaster is predicted. Passive systems, such as using the media to spread messages of interest during heat stress periods, are not reliable especially in a very long heat wave.