By Prof. Olurotimi Coker
One of the reasons for the extremely hot weather recently is the worsening climate change. Extreme heat can affect not only our physical health but, more crucially, our mental health. Scientific studies have recorded that extremely hot weather can cause sleep problems, excessive loss of body water through sweating, muscle cramps, constipation, headaches, and severe dehydration, which can lead to reduced brain function, thereby causing mild cognitive impairments. Similarly, extreme heat can trigger anxiety, mild symptoms of depression, and, within families, precipitate aggression and domestic violence.
Published evidence indicates that extreme heat leads to an increase in visits to medical emergency departments for the treatment of mental disorders. For those already living with mental health conditions, extreme heat may exacerbate disorders such as bipolar conditions (depression and mania), potentially leading to relapses in individuals who have previously received treatment. Elderly people, particularly the vulnerable, may also face an increased risk of dehydration and cognitive impairment, which could mimic dementia (memory loss).
The association between extreme heat and hospital emergency visits has been found to be significantly high, particularly for certain mental health conditions such as drug addiction, excessive alcohol use, generalised anxiety disorder, stress-related disorders, depression, bipolar illness, and delusional disorders. In severe cases, these conditions may even lead to attempted suicide.
Dehydration from extreme heat
One of the most common health consequences of extreme heat is dehydration. In hot weather, we lose water through breathing, sweating, urination, and defecation. This lost body fluid is replenished by drinking water. However, some people unconsciously forget to drink an adequate amount of water. When dehydration sets in, the blood becomes more concentrated, making the heart work harder. The kidneys retain more water, leading to reduced urination. Dehydration can also impair brain function, reducing cognitive performance in areas such as concentration, attention, and memory. In severe cases, it can lead to delirium or confusion.
Common signs and symptoms of dehydration include dizziness, muscle cramps, dry mouth and lips, red eyes, reduced urine output or dark-coloured urine, bad breath, headaches, lethargy, constipation, heat rash, and mild confusion. If lost body fluids are not replenished, dehydration can worsen, leading to severe symptoms such as sunken eyes, dry skin, low blood pressure, increased heart rate, confusion, seizures, and the formation of kidney stones. While moderate dehydration can be reversed quickly by increasing fluid intake, severe cases may require medical attention.
Overcoming dehydration caused by extreme heat
Dehydration can be prevented by consuming plenty of water. The following practices can help reduce the risk of dehydration:
Drink plenty of water thirty minutes before and after meals.
Wear loose, non-synthetic clothing and use a cap or hat to protect your head from excessive heat.
Avoid sweetened beverages.
Seek shade during extremely hot weather or carry an umbrella for protection.
If possible, stay indoors between 12:00 noon and 4:00 pm.
As an alternative to water, consume fruits with high water content, such as watermelon, pineapple, and oranges.
It is important to note that mental health challenges triggered and exacerbated by extreme heat are often unrecognised and underreported. Public health experts should therefore prioritise education and prevention programmes to mitigate the expected rise in mental health issues associated with extreme temperatures. Similarly, mental health professionals should prepare for an increase in mental disorders and stress-related illnesses during periods of extreme heat.
Finally, dehydration can occur even without feeling thirsty. The rule of thumb is that we need to drink more water during extremely hot weather.
Coker, A. Olurotimi, is a Lagos-based Professor of Psychiatry. He can be reached at cokerrotimi@gmail.com.
