By Multimedia Producer Yohannes Lowe
Most of us welcome spells of warm weather, but for many it can be a time of extreme anxiety and stress, which can worsen pre-existing mental health conditions or trigger new symptoms.
Higher temperatures may prevent us from thinking as clearly as we usually do, and can impact our mental wellbeing.
As the UK approaches another heatwave - with temperatures set to soar over the coming days - we look at the impact of heatwaves on mental wellbeing and offer advice on how to cope.
What is the link between the physical effects of intense heat and mental wellbeing?
Heatwave-induced sleeping difficulties can make people more likely to feel depressed, suicidal or isolated, with feelings of loneliness often intensifying.
Hot weather has also been linked to reduced cognitive function and judgment errors, which can trigger feelings of anxiety generally, or anxiety specifically linked to performance.
Hyperthermia - when the body reaches an abnormally high temperature and heat-regulating mechanisms fail to cope - can lead to heat exhaustion, and heatstroke (around 40C), which includes mental dysfunction as a symptom.
"The physical effects of heatwaves - such as hyperthermia, heat exhaustion and heat cramps - are well known and can cause dehydration and insomnia, which can have all kinds of side effects," Linda Blair, who has been a clinical psychologist for 42 years, told ITV News.
"When you can't sleep, it is harder to concentrate. It can lead to impulsivity, anger and a lack of concentration. It is hard to be logical because the emotional side of our brain will dominate and swamp our logic.
"This means we can't carry through on our plans or remember things easily. As a result, we may start to feel bad about ourselves as we are less able to solve the things that are distressing us.
"So, physical effects from heat can cascade into the psychological."
How can heatwaves impact those with pre-existing mental health conditions?
The associated distress that heatwaves cause can lead to a deterioration in the mental health of people with pre-existing conditions.
Soaring temperatures can trigger manic episodes in people living with bipolar disorder, which can result in hospitalisation for psychosis and suicidal thoughts.
Research in Australia, published in the Environmental Health Perspectives journal, found that there is generally a spike in hospital admissions at around 27C, with an increase of 7.3% during heatwaves.
Recent studies have suggested at least a 10% rise in hospital emergency room visits on days when temperatures reach or exceed the top 5% of the normal temperature range for a given location.
"If a heatwave goes on for three days or more with a mean temperature consistently in the 90th percentile or higher, then the effect of those conditions on our moods reaches its highest level," Ms Blair, a chartered member of the British Psychological Society, explained.
Psychologists are keen to stress that there is no direct relationship between heat and its effects on us psychologically that we can prove - only associations.
Professor Tahseen Jafry, director of the Mary Robinson Centre for Climate Justice at Glasgow Caledonian University, said her team's research shows people are increasingly presenting themselves in hospitals with mental health issues.
"There is published evidence indicating that there is a relationship between increased temperature rises, humidity and visits to hospitals with mental health illnesses," she said, noting that evidence in this area is still "thin on the ground".
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Why does the heat affect our mental health?
The hot weather means many people experience interrupted sleep - or no sleep at all - during heatwaves.
Sleep is so important as it performs a restorative function in "recharging" the brain at the end of each day.
Sufficient sleep, especially the rapid eye movement phase, when most dreaming occurs, facilitates the brain’s processing of emotional information.
Experts say a prolonged period of broken sleep can be a trigger for the onset of, for example, a depressive phase, with poor-quality sleep worsening outcomes for mental health conditions in some people.
Professor Neil Greenberg, professor of Defence Mental Health in the Health Protection Research Unit at King’s College London, said: "It is well recognised that it is harder to sleep when it is very hot."
"A lack of sleep, for any reason, can negatively impact on someone’s mental health and of course the longer that someone goes without good quality sleep, the more likely they are to find it difficult to cope with other stressors and to maintain support relationships."
Intense heat can worsen some side-effects of psychiatric medication, even reportedly making medication less effective in certain cases.
“Some psychiatric medications, including some antipsychotics and antidepressants, might increase our sensitivity to sunlight," Stephen Buckley, Head of Information at Mind, said.
"Some antidepressants can cause increased sweating or muscle weakness, so if you take medication for your mental health, it’s even more important to look after yourself in extreme heat."
“Certain medications prescribed to help manage the symptoms of a mental illness can also make you more susceptible to struggling in the heat," Gemma Thickett, advice and information service manager at Rethink Mental Illness, added.
"For example, antipsychotic medications prescribed for conditions such as schizophrenia can lead to overheating because of the impact they can have on the body’s ability to regulate temperature."
Eco-anxiety and mental health
Eco-anxiety - a chronic fear of environmental doom - can be triggered by heatwaves and the stark images, such as those of wildfires and the after effects of droughts, generated by them.
A 2021 survey carried out by the Office for National Statistics showed that three-quarters of adults in Britain are worried about climate change.
More than 40% of those polled reported feeling anxious about the future of the environment.
Experts have said more people in the UK will likely experience a form of eco-anxiety as extreme weather events brought on by climate change become more commonplace.
“Heatwaves can make us more aware of and anxious about the climate emergency, and this anxiety may in turn exacerbate existing mental health problems," Mr Buckley added.
"It’s understandable to feel worried or even scared by the climate emergency. Try to be kind to yourself and seek help if you need it – and remember you’re not alone in feeling this way."
What can you do to best protect your mental health during the heatwave?
Keeping medications out of the sun and remembering to take them
Avoiding alcohol and dangerous substances
Staying in touch with friends and loved ones and practicing self compassion
Taking steps to ensure a good night sleep in the heat, including: using thin sheets, keeping to your usual bedtime and routines as best as possible, chilling your socks and staying hydrated
Speak to medical professionals if you notice a worsening of symptoms
You can contact the organisations listed below for help, support and information:
CALM, Campaign Against Living Miserably runs a free and confidential helpline and webchat. It also supports those bereaved by suicide, through the Support After Suicide Partnership (SASP). Call 0800 585858 (daily, 5pm to midnight).
Mind is a mental health charity which promotes the views and needs of people with mental health issues. It provides advice and support to empower anyone experiencing a mental health problem, and campaigns to improve services, raise awareness and promote understanding. Call 0300 123 3393 or email firstname.lastname@example.org
Samaritans is an organisation offering confidential support for people experiencing feelings of distress or despair. Phone 116 123 (a free 24 hour helpline) or email email@example.com
YoungMinds is a resource with information on child and adolescent mental health, but also offers services for parents and professionals It is the UK’s leading charity fighting for children and young people's mental health, and wants to make sure all young people can get the mental health support they need when they need it. Text YM to 85258 or call 0808 802 5544 (Monday to Friday, 9.30am-4pm).
Shout is a 24/7 text service, free on all major mobile networks, for anyone struggling to cope and in need of immediate help. Text SHOUT to 85258.
SOS Silence of Suicide provides a listening service for children and adults who need emotional support, understanding, compassion & kindness. Phone: 0300 102 0505