Heat summary - Chapter 2: temperature and mortality
This page summarises Chapter 2 of the Health Effects of Climate Change (HECC) report with a focus on the impact of heat on temperature and mortality. This is part of the science and stats section for the hazard: heat.
Applies to England
CCHS navigation menu:
CCHS homepage
Topic: climate-related hazards
Hazard: all climate-related hazards, heat
Part of: heat summary - full HECC report
Key resources for HECC Chapter 2:
- Heat summary - Chapter 2: temperature and mortality
- Chapter 2 full report (pdf)
Heat summary of Chapter 2
Because of climate change and the UK’s ageing population, heat-related deaths in the UK are projected to increase significantly in the future in the absence of future adaptation, due to climate change and the UK’s ageing population.
When the weather gets hot, many people welcome the heat, and those who are more at risk from the effects of heat may not think of taking action to protect themselves.
Whilst hotter temperatures can feel uncomfortable for healthy adults, they can be more dangerous for certain groups. The health impacts of hot weather are not felt equally among the population and interventions should seek to address inequalities.
Vulnerable groups falling ill during hot weather include:
- those over the age of 65
- children and babies
- those with underlying health conditions or taking certain medications
- those who are already dehydrated through illness or alcohol/drug dependence
- pregnant women
- homeless people
- people living alone with poor mobility
Health risks particularly include:
- cardiac illness (to do with the heart)
- respiratory illness (to do with breathing)
- cerebrovascular illness (to do with blood flow to the brain)
- psychiatric conditions (to do with mental health)
Mental health effects including increased suicide risk, though knowledge gaps remain.
Some actions that can be taken to reduce the health risk of hot weather include behavioural changes, national alert systems, improvement to housing, and increasing green space.
Extreme temperatures are already associated with excess deaths every year in the UK, and managing this risk is important to ensure a resilient healthcare system.
Many of the deaths that occur during heatwaves are likely preventable, and mortality does not only occur in areas of the highest temperatures.
People living in urban areas, or south-facing top-floor flats also face a greater risk. Homes that don’t have much shading or only have windows on one side of the property or which can’t open properly can also get very hot during heatwaves.
To cool down during a heatwave, actions include:
- staying out of the heat and cooling yourself down
- keeping your environment cool
- looking out for others
- putting up external shading
- using pale, reflective paints
- improving insulation
- growing leafy plants and trees near windows (because they provide shade)
The impact of increasing temperatures on public transport also needs to be considered in planning. Deep tube lines in London can exceed outside temperatures by an additional 10°C.
It is possible that in future, overheated transport could lead to a loss of workdays as heat-vulnerable individuals are less able to travel during extreme heat.
Education might also be impacted by hot weather: a survey of 135 teachers found that 100% of respondents felt hot weather impacted the productivity of students.
There is a lack of research about the risks of hot weather on those in prison facilities, however restrictions within this environment might make it harder for people to protect themselves against hot weather risks.