India is facing its hottest summer. Eastern India suffered its hottest April since temperature recording began in 1901. Very unusually, Kerala recorded two heat-related deaths in April. While Indian Meteorological Department (IMD) predicted the number of heatwave days in May will be 5-8 days above normal in some regions, the actual number will be known only in June. What exactly is a heat wave?
Simply put, heat waves happen when normal day and night temperatures are higher than normal for at least two days in a row. According to the IMD, a heat wave occurs when actual maximum temperature is ≥ 45°C in the plains and ≥30°C in the hills. In coastal regions, a heat wave is declared when actual maximum temperature is ≥ 37°C and departure from normal is ≥4.50°C. A heat wave can also occur when the temperature of a region is 4.5- 6.4°C higher than normal; if this is >6.4°C, then it is a severe heat wave. If this happens for two days continuously, then the heat wave is declared on the second day.
In India, heat waves typically occur from March to June, at times extending till July, with the peak month being May. Heat waves can be made worse by winds blowing from regions suffering from drought and dry soil conditions even if they are far. Another cause is humidity, which is why in coastal areas the heatwave threshold is lower. Traditionally, five-six heat-wave events occur every year over north India. The negative impact of heat waves also depends on social factors like clothing, occupation, accommodation and physiological factors like health, fitness, age, level of acclimatisation and so on.
Generally the most vulnerable during this time are infants, children, pregnant women and the elderly. But the negative impact of a heat wave is largely preventable. What can you do to keep yourself safe?
Follow these tips:
Avoid going out or exercising during the hottest time. If you have to step out, stay in the shade.
Carry water bottles, a handheld fan, cap and umbrella. Make sure you use sunscreen.
Wear loose clothes in light colours. Cotton is the best.
Keep drinking water at regular intervals. Don’t wait till you are thirsty.
Draw your window curtains and close the windows and doors during the hottest part of the day. Open them in the late evening and early morning.
In dry areas, coolers are very effective. In humid areas, air conditioners are better. But set your AC at 24°C, as this saves electricity and is good for the body.
Watch out for these symptoms: feeling very tired, sweating excessively, having cramps or a headache, vomiting, high temperature, feeling dizzy or breathing fast. You could be going in for a heat stroke. Call an adult and see a doctor immediately.
