Guidance

Heat summary - Health Effects of Climate Change (HECC) full report

The 2023 Health Effects of Climate Change (HECC) report highlights how climate change intensifies and increases the frequency of extreme weather. This page provides key takeaways from the HECC report, specifically on the hazard: heat.

Applies to England

Summary

Climate change is causing more intense and frequent heat episodes, which can have a negative impact on health. Higher temperatures increase heat-related illnesses, mental health issues, and respiratory problems. Vulnerable populations, like low-income areas and older people, face greater health risks due to existing inequalities, poor housing and healthcare factors. As demand on healthcare systems rise during heatwaves, they can become overwhelmed.

Climate change as un underlying driver

Increased heat due to climate change is a hazard which may impact public health issues. Rising temperatures are expected to make heatwaves more intense, more frequent and last longer, affecting physical and mental health and access to resources like water, food and healthcare.

Figure 1. Visual representation of how climate change is an underlying factor

  • heat causes physical health issues: including heatstroke and cardiovascular issues

  • heat causes physical health issues which affects mental health issues: poor physical health can worsen mental health conditions like anxiety and PTSD

  • heat and air pollution causes respiratory illness and burden: combined heat and pollution may amplify respiratory issues, which is likely to increase healthcare system demands

Inequality as a cross cutting issue

Heat disproportionately affects vulnerable populations (for example low-income communities or elderly people) due to societal issues such as poor housing and healthcare access, making them more vulnerable to greater health risks.

Figure 2. Visual representation of how inequality is a cross-cutting issue

  • heat and poor housing cause health inequalities: low-income areas face more heat exposure due to poorly insulated housing, raising illness and mortality risks as well as further worsening inequalities

  • heat causes hospital admissions which cause system strain: vulnerable populations face more heat-related illnesses, straining healthcare systems

  • vulnerable populations cause health inequalities: those with limited healthcare access face greater impacts from heat, widening health gaps

Mental health as a compounding factor

Heat impacts have been found to worsen mental health. Extreme heat, economic strain, and healthcare pressure lead to worsening mental health, including anxiety and depression.

Figure 3. Visual representation of how mental health is a compounding factor

  • heat causes mental decline which causes physical decline: psychological stress from heat worsens physical health as mental health issues affect chronic disease management

  • heat causes workplace stress which causes financial strain: heat affects work productivity, causing economic stress, which worsens mental health

  • prolonged heat causes long-term deterioration: prolonged heat exposure and stress lead to long-term physical and mental health issues

Health system resilience and capacity

Health systems should consider how they can adapt to become resilient to extreme heat events, including the management of risks to service delivery and safety.

Figure 4. Visual representation of health system resilience and capacity

  • heat causes healthcare demand which causes system overload: heatwaves lead to hospital surges, overwhelming systems and leading to higher mortality

  • heat causes overworked emergency services: strained services during heatwaves delay critical care, increasing health risks

  • heat and existing issues cause crises: pre-existing healthcare challenges are worsened by heat, leading to ongoing system overload

Updates to this page

Published 19 December 2024

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