Heat waves have a huge impact on our physical and mental health. Doctors often fear them, as emergency rooms quickly fill with patients suffering from dehydration, delirium and fainting.
Recent studies suggest an increase of at least 10% in hospital emergency room visits on days when temperatures reach or exceed the upper 5% of the normal temperature range for a given location.
Rising temperatures can also aggravate symptoms for people with mental health conditions. Heat waves, as well as other weather events such as floods and fires, have been linked to an increase in depressive symptoms in people with this illness, and with an increase in anxiety symptoms in people with an eating disorder. generalized anxiety.
There is also a relationship between daily high temperatures and suicide and suicide attempts. And, broadly speaking, for every degree of increase in the average monthly temperature, deaths related to mental health increase by 2.2%. Relative humidity spikes also cause a higher number of suicides.
Humidity and temperature—both of which change as a result of human-induced climate change—have been causally linked to increased manic episodes in people with bipolar disorder. This disease state causes significant damage and can lead to hospitalization for psychosis and thoughts of suicide.
Other problems arise from the fact that the efficacy of important drugs used to treat psychiatric illness can be reduced by the effects of heat. We know that many drugs increase the risk of heat-related death, for example antipsychotics, which can suppress thirst and make people dehydrated. Some drugs act differently depending on a person’s body temperature and degree of dehydration, such as lithium, a very powerful and widely used mood stabilizer, which is frequently prescribed for people with bipolar disorder.
confused thinking, aggressive behavior
Heat can also affect mental health and the ability to think and reason in people who do not have a mental disorder. Research shows that the areas of the brain responsible for framing and solving complex cognitive tasks are affected by heat stress.
A study of Boston students found that those in rooms without air conditioning during a heat wave performed 13% worse than their peers on cognitive tests and had 13% less reaction time.
When people are not thinking clearly because of the heat, they are more likely to become frustrated, and this, in turn, can lead to aggression.
There is strong evidence linking extreme heat to an increase in violent crime. Even a simple one or two degree Celsius increase in ambient temperature can lead to a 3-5% increase in aggression.
By 2090, it is estimated that climate change could be responsible for an increase of up to 5% in all categories of crime, globally. The reasons for these increases involve a complex interplay of psychological, social, and biological factors. For example, a brain chemical called serotonin, which, among other things, keeps aggression levels in check, is affected by high temperatures.
Hot days can also exacerbate eco-anxiety. In the UK, 60% of young people surveyed said they are very or extremely concerned about climate change. More than 45% of those surveyed said that feelings about the weather affected their daily lives.
There is still much we don’t understand about the complex interplay and feedback loops between climate change and mental health, especially the effects of heat waves. But what we do know is that we are playing a very dangerous game with the planet. Heat waves, and the effects they have on our mental health, are an important reminder that the best thing we can do to help ourselves and future generations is to act against climate change.