7 ways that heatwaves exacerbate existing inequalities

Heatwaves are our new normal, it’s just a case of how often and how bad they will be. The UK is particularly at risk, with predictions that summer temperatures and extreme hot days could rise up to 50% faster than the average rate of global warming.  

The people most impacted by climate change in the UK are those who are already disadvantaged, often in multiple ways.  

Here are seven ways that heatwaves exacerbate inequalities: 

Financial inequality 

People on low incomes are more likely to live in housing not suited to heat and are twice as likely to live in places that are significantly hotter than neighbouring areas due to the ‘urban heat island’ effect. This is made worse by the fact that people living in low-income areas are more than twice as likely to be burgled than those living in affluent areas, which can generate anxiety around opening windows and doors in order to keep cool. And alternative methods for managing heat, such as turning on a fan or closing the curtains—which may mean turning lights on— can create extra costs.  

Health inequality 

The adverse impacts of heat on health are greater for people experiencing health inequalities. This is something which particularly impacts people in poverty; ethnic minority community groups (especially Pakistani and Bangladeshi communities); Gypsy, Roma and Traveller communities; people who experience homelessness; people who experience drug and alcohol dependence; ‘vulnerable’ migrants; sex workers; people in contact with the justice system; and victims of modern slavery. 

Some health conditions, such as diabetes, heart conditions, and mental health issues, increase risks of heat. Heat impacts how the body uses insulin, so people with diabetes can get dehydrated more quickly, which can raise blood sugar, which causes more urination, and in turn increases dehydration further.  People with Chronic obstructive pulmonary disease (COPD) can experience increased flare-ups with higher temperatures as breathing in hot air can worsen airway inflammation. Poor air quality exacerbates this challenge, and air pollution is worse on hot days because the high temperatures and sunlight cause pollution and naturally occurring nitrogen oxide in the air to create a ‘smog’ of ground-level ozone gas. Heat extremes are associated with increased mental health related hospital admissions and suicidality and also significant correlations are found between exposure to higher temperatures and sunlight and bipolar disorder episodes that require hospital admission. 

In addition, many common medications affect how the body regulates heat, including those used to support urinary incontinence, Parkinson’s disease, respiratory disorders, peptic ulcers, hay fever, high blood pressure, fluid retention, ADHD, depression, and anxiety. 

Racial inequality 

People from ethnic minority communities are disproportionately represented in low-income households and are comparatively more likely to live in poorly adapted housing, which are exposed to higher temperatures and higher air pollution. The profound health inequalities experienced by people from ethnic minority communities’ places Black and Asian women at even greater risk of heat related pregnancy complications. Heatwaves are linked to foetal strain, early labour and lower birth weights—particularly for those on lower incomes or from ethnic minority communities—and women from ethnic minority communities are at greater risk of pregnancy complications such as pre-eclampsia, which increases heat impacted challenges such as high blood pressure, swollen feet and hands, vomiting, and blurred vision.  

Gender and sexual orientation inequality  

Although insufficiently understood at this time, there are indications that gender and sexual orientation impact experience of heat.  

LGBTQ+ people have disproportionately worse experiences of healthcare and health outcomes that will be exacerbated by heat. For example, LGBTQ+ people are more likely to live in poverty,  be economically inactive, experience poor mental health, and have avoided medical treatment for fear of discrimination. 

Women are particularly vulnerable during pregnancy as outlined above, particularly those from lower socio-economic groups. And as most domestic violence victims are women, that places them at greater risk during heatwaves when intimate partner violence increases with temperatures.   

Disability inequality 

Disabled people are disproportionately represented in low-income households, and often live in poorly adapted housing, including in relation to heat. Risk information is not always designed or delivered in an accessible format for people who are deaf or have hearing loss, who are blind or have low vision, or who have diminished cognitive ability— including people living with dementia or Alzheimer’s. And many disabilities can make it harder to regulate temperature, for example: Multiple Sclerosis, autonomic nervous system issues (such as PoTS), people with spinal cord injuries where the sweating function is affected, and people living with syndromes including Ehlers-Danlos syndrome. 

Age inequality  

Babies, children, and young people are disproportionately impacted by environmental changes as growing minds and bodies are greatly impacted by heat, especially when co-occurring with air pollution that worsens on hot days. For example, academic performance is lower during heatwaves, particularly in low-income areas. Whilst air pollution is linked to neurodevelopment and cognitive ability, reduced reading and math abilities, adolescent high blood pressure, and poor mental health by the age of 18. Exposure to air pollution in schools is high and many school buildings are poorly adapted for heat. 

Babies, children, and teenagers are more at risk of heat stress than adults because they weigh less, absorb heat more rapidly, produce more heat when active, sweat less, and can lose body fluid quickly. Similarly older adults are particularly at risk of dehydration, due to the body’s fluid reserve becoming smaller with age, the sense of thirst becoming less acute, and compounding issues such as diabetes and dementia. Dehydration is a risk factor for falls in older people and is associated with pressure ulcers, faecal impaction and cognitive impairment. Lifestyle factors can also play a role, including older men being reluctant to drink significant amounts of fluid because of enlarged prostates and more frequent urination. Whilst drinking caffeinated drinks, such as tea and coffee, can increase fall risks. 

Power inequality 

The people most impacted are often those heard least in environmental debate and decision making. These diverse social groups have told the Everyone’s Environment programme that they want to be involved in decision-making that affect their lives and to help identify solutions to environmental challenges. 

Charities and funders have agency to influence action to mitigate the extent of climate change and to support society to adapt to living with heatwaves and other environmental impacts. Perhaps most importantly, we can raise the voices of those most impacted to ensure that society’s response to the environmental crises builds a fairer, healthier, and more sustainable future for everyone. 

These examples show how heat effects fall on the most disadvantaged groups in society, see more examples of how our changing climate and natural world are impacting these groups in our Everyone’s Environment publications.