Oxfam East Africa
                                ? Credits

                                Heatwaves

                                  Overview

                                  Heatwaves, or heat and hot weather that can last for several days, can have a significant impact on society, including a rise in heat-related deaths. Heatwaves are among the most dangerous of natural hazards, but rarely receive adequate attention because their death tolls and destruction are not always immediately obvious. From 1998-2017, more than 166 000 people died due to heatwaves, including more than 70 000 who died during the 2003 heatwave in Europe. 

                                  Population exposure to heat is increasing due to climate change. Globally, extreme temperature events are observed to be increasing in their frequency, duration, and magnitude. Between 2000 and 2016, the number of people exposed to heatwaves increased by around 125 million. 

                                  While the effects of heat may be exacerbated in cities, due to the urban heat island (UHI) effect, the livelihoods and wellbeing of non-urban communities can also be severely disrupted during and after periods of unusually hot weather. 

                                  Heatwaves can burden health and emergency services and also increase strain on water, energy and transportation resulting in power shortages or even blackouts. Food and livelihood security may also be strained if people lose their crops or livestock due to extreme heat.

                                  Impact

                                  The health impact of a heatwave depends on the intensity and duration of the temperature, the acclimatization and adaptation of the population, and the infrastructure and preparedness. 

                                  Exposure to heat causes severe symptoms, such as heat exhaustion and heat stroke – a condition which causes faintness, as well as dry, warm skin, due to the inability of the body to control high temperatures. Other symptoms include swelling in the lower limbs, heat rash on the neck, cramps, headache, irritability, lethargy and weakness. Heat can cause severe dehydration, acute cerebrovascular accidents and contribute to thrombogenesis (blood clots). 

                                  People with chronic diseases that take daily medications have a greater risk of complications and death during a heatwave, as do older people and children.

                                  Reactions to heat depends on each person’s ability to adapt and serious effects can appear suddenly. This is why it is important to pay attention to the alerts and recommendations of local authorities.

                                  WHO Response

                                  The magnitude of human costs from heatwaves can be reduced if adequate emergency prevention, preparedness, response and recovery measures are implemented in a sustainable and timely manner.

                                  WHO works with the health sector to strengthen governance, preparedness and response to heatwaves, by developing contingency plans that map the risks, vulnerable populations, available capacities and resources. These plans also include early warning systems and ensure vulnerable populations, such as those in health facilities, nursing homes and schools have adequate provision of cooling equipment.

                                  As the health cluster lead for global emergencies, WHO works with partners to respond to: 

                                  • ensure appropriate food supplementation;
                                  • restore primary care services, like immunization, child and maternal health, and mental health;
                                  • assemble mobile health teams and outreach;
                                  • conduct epidemic surveillance, early warning and response;
                                  • call for emergency funding to support health action.

                                  166 000 people

                                  died

                                  More than 166 000 people died due to extreme temperatures between 1998-2017

                                  Find out more

                                  250 000

                                  additional deaths

                                  An additional 250 000 deaths each year from climate-sensitive diseases from 2030 onward

                                  Find out more

                                  175 million

                                  more people

                                  In 2015 alone, 175 million additional people were exposed to heat waves compared to average years

                                  Find out more

                                  Publications

                                  All →
                                  Thumbnail - publication - Heatwaves and Health

                                  Heat or hot weather that lasts for several days, often referred to as “a heatwave” can have a significant impact on society, including a rise...

                                  The most important actions to take during a heat-wave are: to avoid or reduce exposure, to communicate risks effectively, to take particular care of vulnerable...

                                  Heat-waves : risks and responses

                                  High air temperatures can affect human health and lead to additional deaths even under current climatic conditions. Heat waves occur infrequently in Europe...