Explained: Heatwave, its signs, symptoms and measures for protection

Chandigarh, May 16

Heatwave is defined based on the temperature thresholds over a region in terms of actual temperature or its departure from normal.

Heatwave is considered if maximum temperature of a station reaches at least 40 degrees Celsius or more for plains and at least 30 degrees Celsius or more for hilly regions.

Heatwave is when departure from normal is 4.5 degrees Celsius to 6.4 degrees Celsius or actual maximum temperature is more than or equal to 45 degrees Celsius.

Severe heatwave is when departure from normal is more than 6.4 degrees Celsius or when actual maximum temperature is more than or equal to 47 degrees Celsius.

North western Indian states of Punjab, Haryana, Chandigarh, Uttar Pradesh and Rajasthan are especially prone to heatwave conditions.

The health impacts of heatwaves typically involve dehydration, heat cramps, heat exhaustion and/or heat stroke.

The signs and symptoms are as follows: 

Heat Cramps: Ederna (swelling) and Syncope (Fainting) generally accompanied by fever below 39 degrees Celsius i.e.,102 degrees Fahrenheit. 

Heat Exhaustion: Fatigue, weakness, dizziness, headache, nausea, vomiting, muscle cramps and sweating. 

Heat Stroke: Body temperatures of 40 degrees Celsius i.e., 104 degrees Fahrenheit or more along with delirium, seizures or coma. This is a potential fatal condition.

The measures one should take to minimise the impact during the heatwave are:

*Drink sufficient water and as often as possible, even if not thirsty.

*Avoid going out or working in the sun, especially between noon and 3pm.

*Wear lightweight, light-colored, loose, and porous cotton clothes.

*Avoid strenuous activities when the outside temperature is high.

*While travelling, carry water with you.

*Avoid alcohol, tea, coffee and carbonated soft drinks, which dehydrate the body. 

*If you work outside, use a hat or an umbrella and also use a damp cloth on your head, neck, face and limbs.

*Do not leave children or pets in parked vehicles.

*If you feel faint or ill, see a doctor immediately.

*Use ORS, homemade drinks like lassi, lemon water, buttermilk, etc, which help to re-hydrate the body.

*Keep animals in shade and give them plenty of water to drink.

*Keep your home cool, use curtains, shutters or sunshade and open windows at night.

*Use fans, damp clothing and take bath in cold water frequently.