How extreme temperatures mess with our minds, not just our planet

We’ve almost become completely desensitised to hearing about new record sea levels or temperatures being reached. But every time these records get broken again, it’s not just our livelihoods and environments that suffer, it’s our mental wellbeing too.

The link between mental health and the climate crisis spans well beyond climate anxiety, but this is the most prominent (and maybe the only) phenomenon focused on by policymakers. Defined by Mental Health UK as the ‘sense of fear, worry, or tension linked to climate change’, current policymakers almost solely focus on the anxiety that arises following natural disasters such as flooding. Granted, research shows that one third to one half of those who experienced a natural disaster could face mental health disorders including PTSD, depression, or anxiety; and the increasing rate of these disasters means that, inevitably, more and more people will suffer from these conditions than ever before. However, the impact of climate change on our mental health actually permeates our everyday lives in more sinister ways than policymakers accept – problems do not just appear in the face of disaster.

Chemicals such as serotonin and dopamine … are thought to be the neurotransmitters involved in thermoregulation, and so experience dysfunction during periods of extreme heat

Even the heatwaves that we’ve had to grow accustomed to are associated with a 9.7% increase in hospital admissions for mental illnesses. This goes as far as having a 49.6% increase in suicides during the 1995 heatwaves in England and Wales, with further research suggesting how suicide rates rise with every degree increase in ambient temperature. Behind all of these studies and statistics are real people and real lives taking adverse turns – if this doesn’t call for policymakers to wake up to the realities of climate change worsening mental health, I don’t know what will.

Diving deeper into the consequences of rising heat, it both increases the release of the stress hormone cortisol and alters the brain’s activity and connectivity. Heat affects the function of neurotransmitters, the chemicals the brain uses to communicate both within the organ and to the rest of the body. Chemicals such as serotonin and dopamine – commonly known as happiness chemicals – are thought to be the neurotransmitters involved in thermoregulation, and so experience dysfunction during periods of extreme heat, combining an inability to tolerate heat with the risk of depression.

Subsequently, those with existing mental health conditions are even more significantly impacted – medications such as antidepressants target these neurotransmitters, and the additional stress and discomfort from heat can cause cause more intense depressive episodes, according to Cherly Groskopf, licensed marriage and family therapist.

The stress and discomfort from extreme heat has further been shown to affect our behaviour, memory, and cognition, regardless of pre-existing mental health conditions. As people generally sleep worse during hotter temperature spells, and have an increased mental load while forced to work in non-optimal conditions, we find ourselves significantly more irritable and impulsive. One experiment found that hot conditions made participants more likely to destroy others’ assets in a game, even when they didn’t benefit from this. A study in Shanghai also found that cognitive performance also declines with heat stress, and Groskopf further highlights that heat stress can even cause inflammation that damages brain cells, impacting memory and learning capacities.

The rise in heat and natural disasters have tangibly negative effects on mental health in the entire population, and symptoms will only worsen for those with pre-existing conditions

Considering these negative mental effects of heat, the clear solution is to cool down one’s environment. Yet this then highlights a further exacerbating factor: as lower income communities are much less likely to have access to facilities like air conditioning in their homes or schools, they face an even greater mental health threat from high heat conditions. Looking at the effects of urban heat (the reflection of heat from concrete as well as urban areas being more densely populated), homes in these areas are less likely to be air-conditioned and residents are more likely to be from a BAME background, due to an inverse correlation between income and being from a minority background. The adverse mental effects of heat are therefore even more adverse for those from lower-income and minority backgrounds, with very little they can do about it.

It seems incredibly clear that both the rise in heat and natural disasters have tangibly negative effects on mental health in the entire population, and symptoms will only worsen for those with pre-existing conditions. Coming back to climate anxiety, even this is not limited just to anxiety surrounding natural disasters. Negative climate-related emotions, known as ‘eco-emotions’, are found all across the globe, and arise from a growing awareness of the worsening climate crisis and its effects. 59% of respondents in a survey of 10,000 young people across 10 countries said they were very or extremely worried about climate change. Therefore, it’s not only the studied effects of climate change on mental health conditions that are significant, but what is arguably an epidemic of general anxiety about our future that is gripping the globe.

Yet, only 36% of countries mention climate change-related mental health impacts in their adaptation policies. In the UK, any policies that do address the link between climate change and mental health focus on pushing measures like flood defences to minimise consequences like PTSD – but this misses a clear need for actual climate mitigation efforts which would in turn help to address the myriad of damaging mental health effects found across the population. Until policymakers recognise climate change to be a physical and mental crisis, they remain unable to implement policies that will fully protect and support us.