ABSTRACT
Extreme temperatures considered in this chapter cover cold waves and heatwaves, both of which are defined by periods of extremely cold or extremely hot temperatures over consecutive days measured in comparison to the usual temperatures experienced at that location for that time of year. Both result in the occurrence of excess deaths, based on the expected rate of fatalities for that time period and in that location, as well as other health impacts such as hypothermia and frostbite during periods of extreme cold and heat stress and heat stroke during periods of extreme heat. Infrastructure and critical services can be impacted during extreme temperature events, with both cold waves and heatwaves often leading to a loss of electricity, which causes conditions to deteriorate further. Heatwaves are becoming more problematic due to the urban heat island effect where the infrastructure of urbanised areas absorbs and transfers heat back into the surrounding environment, causing temperatures to be hotter than in bordering semi-urban and rural areas. Anthropogenic climate change is also leading to increases in the intensity, frequency and duration of heatwaves across the globe. While risk assessment and management of extreme temperatures is lacking in comparison to many other environmental hazards, extreme heat and heatwaves are the leading cause of natural hazard-related fatality in many countries.
