The WHO Fact Sheet on Climate Change and Human Health has highlighted the magnitude of the problem of extended periods of extreme heat. Global temperatures and the frequency and intensity of heatwaves are expected to rise in the 21st century as a result of climate change. Extended periods of high day and nighttime temperatures create cumulative physiological stress on the human body which exacerbates the top causes of death globally, including respiratory and cardiovascular diseases, diabetes mellitus and renal disease. Heatwaves can acutely impact large populations for short periods of time, often triggering public health emergencies and result in excess mortality, and cascading socioeconomic impacts (e.g. lost work capacity and labour productivity). They can also cause loss of health service delivery capacity, where power-shortages which often accompany heatwaves disrupt health facilities, transport, and water infrastructure. Between 2000 and 2016, the number of people exposed to heat waves increased by around 125 million worldwide. In 2015 alone, 175 million additional people were exposed to heat waves compared to average years. In 2003, 70,000 people in Europe died as a result of the June-August event; and in 2010, 56,000 excess deaths occurred during a 44-day heatwave in the Russian Federation.
April to middle of May is usually the hottest time of year in Myanmar, and record-breaking temperatures have been reported in the last decade. The Kaba Aye station recorded a maximum of 42.5ºCelsius on May 12, 2010, the highest May temperature recorded in the city in 42 years and 0.5º C above the old mark, set in 1998. Eight other temperature records for the same date include Myinmu’s maximum of 47ºC recorded – the highest May temperature in the town since records began 27 years ago; Myingan’s 46.5ºC, the highest May temperature there in 28 years,; and Monywa’s 45.7ºC was the highest in 46 years. The 45.5ºC in Magway was the highest in 37 years and the 45ºC in Mandalay was the highest in 64 years. Meiktila’s 44ºC was the hottest May day in 56 years. These extreme temperatures had resulted in heat-related disorders .During summer 2010, 1,482 were reported and 260 heat-related deaths occurred across Myanmar Heat stress can result in heat stroke, heat exhaustion, heat cramps, or heat rashes. The risk of injuries in workers may be increased, resulting from sweaty palms, fogged-up safety glasses, and dizziness.
The Ministry of Health & Sports ‘Guidelines and Standard Operating Procedures for hyperthermia- defined as a “state of an elevated core body temperature above 37ºC (98.6ºF) in a hot environment and represents a failure of the body’s normal thermoregulatory mechanisms” – has been distributed to health personnel. Three heat exposure syndromes are recognized: heat cramps, heat exhaustion and heat stroke. It is imperative for all health personnel to recognize the presenting features and to give the necessary care at all levels; at home, clinics, OPDs, RHCs. In this respect, the role of support staff is even more important than that of doctors.
(1) Heat Cramps-painful muscle cramps occurring most commonly in the legs of young people following vigorous exercise in hot weather. There is no elevation of core temperature. Admission to hospital not required. Immediate rest in a cool place is advised Stretch muscles and massage gently. Fluid replacement, either intra-venous normal saline 300-500 ml is needed in severe attack, or Oral rehydration salt is needed in mild attacks. Medical attention should be sought if heat cramps are sustained for more than one hour.
(2) Heat exhaustion – an elevation in core (rectal) temperature between 37 – 40ºC (98.6 – 104 ºF) usually seen on undertaking vigorous physical work in a hot environment. Move the patient to a cool, shaded room or air-conditioned place. Lay the patient down and raise his or her legs and hips to increase venous return. Active evaporative cooling is needed. Tepid spray/sponging. Apply cold wet sheet or spray cold water and use fan if available. Start oral hydration. If nausea prevents oral intake of fluids, consider intravenous hydration. Youth may just require aggressive oral rehydration with oral rehydration salt and may require 4-6 litres over 6-8 hours; up to 5 litres positive fluid balance may be required in first 24 hours. Elderly will require more cautious fluid replacement. Intravenous therapy should be guided by clinical state and Urea & Electrolytes. (caution should be taken if decreased or increased Sodium (Na+) ). Normal saline 1 litre over 30 minutes followed by another over an hour, then alternative bottles of 5 % Dextrose water and Normal saline 2 hourly. If hyperthermia is above 39°C or impaired mental status or sustained
(3) Heat stroke- defined clinically as a core body temperature that rises above 40ºC (104ºF) and
that is accompanied by hot, dry skin and central nervous system abnormalities such as delirium, convulsions, or coma. Immediate admission to hospital for (a) patients diagnosed as heat stroke as per the above definition (b) Patients with core body temperature > 38ºC (100.4′ F)with one of the following high risks conditions – elderly people , babies and young children , people with long-term health condition e.g. diabetes, a heart or lung condition or mental disorders ,those already ill and dehydrated (for example, from gastroenteritis or on diuretics) , people doing strenuous exercise for long periods, such as military soldiers, athletes, hikers and manual workers , people with diseases which increase heat production e.g. hyperthyroidism , people who are taking anticholinergics, tranquilizers, diuretics , chronic alcoholics. Once in hospital, start key observations to monitor if critically ill and if any is noted, contact On Call physician, give oxygen, take ECG, start IV access, stabilize airway and breathing.
Raising awareness in the public, administration of first aid measures, replenishing the body fluids, and prompt admission into hospital for heat stroke needs the involvement of all healthcare personnel. With this article, we honour our healthcare workforce; particularly the nurses , and welcome the WHO designating the year 2020 as the “Year of the Nurse & Midwife” in honour of the 200th birth anniversary of Florence Nightingale.
