Heatwaves are silent killers, and the death toll is often recognised only months after the official figures emerge.
If heatwaves were named as storms to highlight the risk they pose, the dangers would be more widely recognised. Indeed, one in Europe in 2017 got more attention when it was nicknamed Lucifer, which kills many more people each year in the UK than any storm.
Heat exposure has also been linked with an increased risk of death or disability among children, older adults, people with chronic medical conditions and those who are obese.
The heatwave that swept through Europe in the summer of 2003 caused an excess of deaths over the normal seasonal average. Extreme heat exposure can be dangerous for those already vulnerable to the heat, such as the elderly or those living in poorly ventilated buildings.
In addition, excessive heat exposure is linked to increased crime rates, domestic violence incidents, and increased instances of road traffic accidents. In the UK, for example, one in six deaths is attributable to extreme heat.
With temperatures in the United Kingdom breaking records this month, what is the impact of heat waves on your health? Because higher temperatures can pose additional challenges for individuals with Physical and Mental Health conditions. Roughly 1,000 to 3,000 people die every year as a result of heat.
Stress-related conditions that are increased by heat waves are known as psychosocial stressors. These include the subjective experience of a perceived threat from hot weather and the social impact of staying outside during these conditions.
The public health implications can be demonstrated by the fact that these psychosocial stressors often result in higher rates of anxiety, depression, aggression, addiction and suicide during extreme heat.
Are heatwaves a consideration for your mental health?
“In recent years, there’s been an increasingly large body of research showing us that heatwaves exacerbate outcomes for those with underlying psychiatric illnesses,” says Dr Laurence Wainwright, (University of Oxford UK).
Rates of suicides go up, and for those with existing conditions, symptoms can be intensified” he adds, noting that for people with conditions such as bipolar disorder, extreme heat can trigger manic phases.
Prof Tahseen Jafry, Glasgow Caledonian University, said: “With increased temperature rises, there is evidence to show that there are more frequent visits to hospitals for mental health, mental illnesses and behavioural and mood disorders.”
A study published in 2007 found a 3.8% increase in suicide rates for every 1°C rise in average temperature above 18 °C. Researchers also found that higher temperatures are associated with increased aggression and violence – possibly due to the impact on various hormones – and can affect cognitive function, leaving people feeling fuzzy-headed. In Australia, where suicide rates were found to be higher on days when temperatures reached above 20 °C (68 °F).
How does heat affect mental health?
There are likely numerous factors at play. Among them, Wainwright notes, is that many people have interrupted sleep during heatwaves. “The evidence shows us that poor-quality sleep or a briefer sleep duration can worsen outcomes in those with major depressive disorder,” with a couple of nights of broken sleep can be a trigger for the onset of their depressive phase”.
He adds that the heat can aggravate some side effects of psychiatric medication or make the medication less effective. Moreover, some medications affect the body’s ability to thermoregulate or otherwise impair individuals’ ability to take appropriate measures.
“The antipsychotics we use in schizophrenia, and bipolar can impact people’s perception of thirst,” says Wainwright. “The body has an excellent way of telling us when we’re thirsty, but when we’re taking these medications, that can be impacted – and during a heatwave that poses problems for heat-related illnesses.”
It is recommended that people with mental health conditions speak to medical professionals if they notice a deterioration in their symptoms or issues related to their medication.
Climate Change on health
Research, published in Nature Climate Change at the Mamoa’s University of Hawaii, who systematically searched for real-life examples of the impact of ten climatic hazards worsened by greenhouse gas emissions on human diseases.
Analysing over 70,000 scientific papers for examples of direct links between known diseases and climate change, the scientists discovered that all the extreme climatic events made more common and more severe by global warming influenced diseases triggered by viruses, bacteria, animals, fungi and plants.
Of 375 diseases analysed, 218 proved to be affected by climate change.
Climate bringing hazards closer
Specifically, researchers found that climate change-related hazards bring pathogens closer to people, with warmer temperatures and more humid environments associated with the increase in precipitation, favouring the proliferation of mosquitoes, ticks, fleas, birds, and mammals which are responsible for the spread of several viruses and bacteria like dengue, the plague, Lyme disease, and malaria.
Mosquito populations, in particular, have found a breeding ground in the aftermath of floods and storms, causing, in turn, an untick in the pathogens they transmit, including West Nile fever and yellow fever. But climate change is also bringing people closer to pathogens.
Eco-anxiety definition. The condition, which the American Psychological Association (APA) describes as "a chronic fear of environmental doom," is widespread.
Eco-anxiety is not currently listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), meaning that doctors do not officially consider it a diagnosable condition.
However, mental health professionals do use the term eco-anxiety within the field of ecopsychology, a branch that deals with people’s psychological relationships with the rest of nature and how this impacts their identity, well-being, and health.
Higher temperatures on the elderly person
In 2020, three heatwaves in England caused 2,556 excess deaths, according to Public Health England, with the elderly worst affected and people with existing health conditions.
The causes of death were primarily related to cardiovascular, kidney and respiratory conditions. In extreme weather, the body can struggle to cool itself down quickly enough and in extreme cases, normally among the very young, elderly and sick, that can result in death.
The elderly are especially prone to heat exhaustion because they produce less sweat, and their ability to dissipate heat is slower than that of a younger person. People who live in hot climates are also at greater risk of hyperthermia, as they spend more time indoors without the help of an air conditioner or a fan.
Lack of fluids due to changes in eating habits, medications and activities can result in dehydration, which worsens hyperthermia.
A minister urged people to watch elderly neighbours in the “extreme heat” because their cardiovascular system must work overtime to keep them cool, particularly for older people and the very young”.
As we age, our bodies find it harder to manage extremes of heat and cold. Any older person already coping with significant health issues will see the coming heatwave challenging if it impacts their heart or lungs.
We know that the most dangerous heart conditions are caused when people, particularly those with underlying health conditions, have no respite from the heat for days and nights on end.
Antonio Gasparrini, of the London School of Hygiene & Tropical Medicine, has estimated that about 950 people in England and Wales are likely to have died because of the heat between July 17 and 19, when there was a record high of 40°C.
Effects on child health and learning
There is some evidence that children’s ability to learn and the quality of their cognitive function can be affected by changes in temperature, humidity, and precipitation patterns. For example, a study published in 2016 found that increased exposure to sunlight could lead to developmental delays among children. The article also noted that children’s mental health could be adversely impacted if exposed to higher solar radiation levels.
The same study also found that excessive heat can increase the number of cases of acute respiratory infections among children. In another study published in 2017, researchers found that high temperatures during the summer months impact academic performance due to a decrease in people’s time outside or when they are not working outdoors.
This study further suggested that high temperatures may cause people to engage less with their community or family members because they spend more time indoors cooling down.
Playing outside during the summer is healthy and promotes benefits from exercise. However, a young child’s body cannot adapt to extreme changes in temperature. Children’s bodies absorb more heat on a hot day and do not sweat as quickly as adults, so they are less able to cool off by sweating.
Catching dehydration early, providing fluids, and removing the child from the heat will prevent a medical emergency.
Before heat stroke symptoms appear, kids often show signs and symptoms of milder heat illnesses, such as heat cramps and heat exhaustion. This often occurs after a child has been exercising or playing in the heat and becomes dehydrated from losing excessive fluids and salt from sweating.
Physical effects of extreme heat exposure
Analysis by the Office for National Statistics suggests respiratory and cardiovascular deaths in particular increase during hot weather, as well as road traffic accidents and drowning.
The primary physical effects of heat exposure are hyperthermia and dehydration. Hyperthermia is a condition where the body’s core temperature goes beyond a normal range, leading to heat cramps, heat exhaustion and potentially death. Dehydration is when the body loses too much water through sweating and breathing (accessible in hot weather), causing low blood pressure, decreased heart rate and loss of consciousness.
Social factors also make extreme heat exposures more dangerous for humans. People may spend more time outdoors during hot weather because they don’t have air conditioning at home to cool them down. This leads to less time spent indoors with people who are sick or elderly residents of nursing homes who cannot leave their rooms during the day.
This can increase the risk of contracting illnesses like the flu or pneumonia. Finally, there are psychological and emotional impacts that prolonged exposure to hot weather may have on people under stress.
For example, it has been found that people exposed to either severe or mild stress during hot weather show increased health-compromising behaviours, such as increased alcohol consumption or smoking cigarettes.
Is the heatwave making you fat?
Researchers at Tel Aviv University, in Israel, found sunlight hitting the skin triggered the release of the appetite-stimulating hormone called ghrelin, resulting in more calories consumed. Men consumed about 17 per cent more calories — up to 300 extra calories every day — between the sunnier months of March and September than they did during the rest of the year.
It’s a phenomenon that does not seem to affect women, whose food intake stayed about the same, probably because the female hormone oestrogen blocks the effects of UV radiation on hunger hormones.
In the findings published in Nature Metabolism, men said their hunger levels rose after even this brief sun exposure, while the women experienced no change in appetite.
Most importantly, if you are exercising outdoors, pay attention to your body temperature to reduce the risk of serious heat-related conditions, including heatstroke.
Exercising in hot weather puts extra stress on your body. If you don't take care when exercising in the heat, you risk serious illness. Both the exercise itself and the air temperature and humidity can increase your core body temperature. To help cool itself, your body sends more blood to circulate through your skin.
Sapper Connor Morrison, a 20-year-old recruit, died this year on the 23 July 22 after passing out during a training session in Suffolk as temperatures soared up to 40°C.
According to the Ministry of Defence, six members of the armed forces have died during training in high temperatures in the past 22 years. They include three SAS reservists who were carrying backpacks weighing up to 27 kg during a 16-mile training march in the Brecon Beacons, in Wales, on one of the hottest days of 2013.
While it’s always important to know how to prevent heat-related illness, elderly people also need to know how to take care of themselves when temperatures soar. The biggest thing that people need to remember is that they can prevent heat-related illness and stay cool with the following methods:
With the world’s population expected to increase by another two billion people by 2050, climate change will likely aggravate existing global challenges.
Owing to high temperatures, rising levels of carbon dioxide in the atmosphere, and changes in rainfall patterns, many parts of the world are already experiencing higher temperatures and changing precipitation patterns.
These weather extremes may indirectly impact mental health and wellbeing, as they can trigger various mental health conditions that are also projected to increase with climate change. Hot weather increases the risk of heat exhaustion and heatstroke, and also heart attacks and heart failure.
Higher temperatures on mental health are a growing concern, both in the States and worldwide. Increased temperatures can lead to increased rates of depression and anxiety disorders, suicide risk, and impairment of mental health services.
Some medications affect the body’s ability to thermoregulate or make the individual more sensitive to the sun. It wasn’t unusual to be mindful of this within an autistic adult home, where a small number had to be observed during summer to prevent sunburn.
Even the smallest amount of sunburn would appear, just as the night shift took over. The patient was annoyed and in pain; they would undoubtedly make the staff know they were going through hell, and the night staff were indeed invited. Tantrums, broken furniture and, in one case, a large old type TV size of a fridge were thrown across the room. Message received, loud and clear.