By Dr Punithavathy Shanmuganathan & Dr Lim Yin Sear
Malaysia is currently experiencing scorching hot weather throughout the country.
As of 17 May, the Ministry of Health had reported 15 cases of heat-related illness, of which four were cases of heatstroke, four due to heat exhaustion and the remaining cases were due to heat cramps.
Cases are expected to rise till mid this year as the heatwave continues and temperatures average between 33°C and 35°C. The continuous elevated temperatures have a negative impact on the public and will potentially lead to heat-related illness ranging from minor conditions such as heat cramps to the more severe condition known as heat stroke.
Heat stroke is a severe heat-related illness and is characterised by increased body temperature (hyperthermia), little or no sweating (anhidrosis), and an altered sensorium, after a period of prolonged exposure to high ambient temperatures. However, anhidrosis is a late finding and may not be present during physical examination. Core body temperatures above 40°C are usually diagnostic, although heat stroke may seldom occur with lower body temperatures.
Early symptoms include behavioural changes, confusion, delirium, weakness, agitation, slurring of speech, nausea, and vomiting. Other possible central nervous system symptoms include seizures, cranial nerve abnormalities, and cerebellar dysfunction. If proper treatment is not promptly given, patients may develop vital organ injury, unconsciousness, multiple organ failure, and ultimately coma and death.
Heat exhaustion is the body’s response to excessive sweating, which leads to enormous amount of loss of water and salt. It is characterised by heavy sweating, dizziness, thirst, decreased urine output, nausea, and vomiting. The body temperature may be elevated (less than 40°C) or normal. Upon examination, there will be cool, clammy skin. It is not corrected or fails to respond to treatment, this may lead to heatstroke.
Heat cramps are usually seen among people who sweat a lot during arduous activity. It occurs in people who only drink water or hypotonic solutions. As we sweat, our body is depleted of salts and fluids. These low salt levels cause painful body cramps especially in our muscles. The calves, thigh muscles, and shoulders are the most affected muscles.
Heat rash is skin irritation due to excessive sweating. Due to the irritation, there may be skin redness, red spots, or rash over the neck, chest, and elbow creases. These may cause discomfort and skin itchiness. Recurrent and prolonged exposure to the heat may lead to chronic dermatitis of the skin.
The symptoms and signs of heat stroke are almost like other types of diseases involving the central nervous systems like meningitis or encephalitis. In early May 2023, it was incorrectly reported that the death of a 12-year-old boy in Kluang, Johor, was due to heat stroke. He was presented with fever, shivering, agitation, and seizure. However, investigation revealed the cause of death was 'septic shock secondary to meningoencephalitis' and it was not related to heat stroke as previously reported.
Thus, as the symptoms of disease involving the central nervous system (CNS) and heat stroke can present similarly, it is important to seek proper medical advice from trained medical personnel to come to a correct diagnosis to initiate the suitable treatment.
Treatment of heat-related illnesses
For minor heat-related illness, treatment includes rapid cooling of body temperature. The patient should be moved to a cool environment, such as indoors. Clothing should then be removed or loosened to increase heat loss through the skin. A combination of a cool water spray with constant air flow over the body, such as with a fan or air-conditioning unit, is also an effective method. Other cooling methods such as cold-water immersion can also be used. However, the patient should not be wrapped in wet towels because this will act as insulation and may increase the body temperature instead.
For major heat-related illnesses like heat stroke, it is vital to initiate very quick and effective cooling measures. The patient needs to be brought to a cool and shady environment. Unnecessary clothing should be removed, and tepid sponging must be initiated. Cool compression is to be applied at the armpits, neck, groin, and head. For these patients, an ambulance would need to be arranged to transfer them to the nearest hospital for further management as failure to recognise and manage heatstroke correctly can result in irreversible injury and death.
Preventive measures to stay safe and healthy
During these times, it is also vital to remain alert and track the current weather forecast, especially the heat index, which can easily be accessed on the MetMalaysia website.
The public is advised to reduce outdoor activities and to seek treatment immediately if they exhibit symptoms of heat stroke. It is also discouraged to wear dark-coloured clothes as they may absorb more heat thus increasing body temperature. Light-coloured and loose-fitting clothes will allow sweat to evaporate and cool the body.
Body rehydration is essential as part of the treatment. Feeling thirsty is not a reliable sign of a person needing more fluid. A better indicator will be the colour of urine and a dark yellow colour may indicate dehydration, thus requiring more fluid administration.
In mild cases, rehydration can be achieved by increased oral intake of water, or preferably isotonic drinks to maintain the balance of electrolytes in the body. However, if the patient is unable to tolerate oral fluid, confused or unconscious, then IV (intravenous) fluids should be initiated for rehydration and electrolyte replacement. It is also advised to refrain from drinking sweet, carbonated drinks as well as alcoholic beverages. Drinking too much coffee and tea is also not advisable as they have diuretic effect and will lead to more loss of fluids.
Extra preventive measures in school children
For children, their bodies may take longer to increase sweat production as compared to adults. Infants and younger children also have more trouble regulating their body temperature, in part because they often do not recognise the importance of drinking water. Parents and caregivers should monitor the amount of water their child drinks and encourage them to drink plenty of fluid.
School teachers also need to play a role in ensuring that their students are drinking fluids regularly and several schools in the Klang Valley have since taken proactive measures through periodic announcements to remind and encourage them to consume drinks to stay hydrated.
The Ministry of Education has taken steps in the right direction by temporarily halting outdoor activities until the weather condition improves.
Additionally, vehicles parked under the scorching sun can get extremely hot and a child should never be left unattended in a parked vehicle. They will be susceptible to confinement hyperpyrexia (a subtype of heatstroke) which is a preventable condition.
Overall, adhering to the abovementioned preventative steps and staying well-informed are extremely crucial and will reduce the risk of ourselves and our children developing heat-related illnesses.
Dr Punithavathy Shanmuganathan is Senior Lecturer in Family Medicine
Dr Lim Yin Sear is Senior Lecturer in Paediatrics, at the School of Medicine, Faculty of Health and Medical Sciences, Taylor’s University