Delhi-NCR Boils Under Extreme Heatwave, IMD Issues Orange-Red Alert As Mercury Nears 46 Degrees

New Delhi: The entire northern and central India, including Delhi, is currently in a state of sweltering heat. The India Meteorological Department (IMD) on Friday has issued a heatwave warning for Delhi-NCR and the surrounding plains, ranging from a heatwave to a severe heatwave. The maximum temperatures in Delhi have hovered between 44 and 46 degrees Celsius.

What did IMD say?

The IMD has issued alerts considering the severity of the situation. But there is a difference between a normal heatwave and a severe heatwave and the effect of these colour-coded weather alerts (Red/Orange Alerts) on our bodies.

What is the difference between a heatwave and a severe heatwave?

According to department rules, a heatwave occurs when the maximum temperature in a location in the plains reaches at least 40 degrees Celsius or more. 

If the temperature directly reaches between 45 degrees Celsius and 46.9 degrees Celsius it is declared as heatwave.

Severe heatwave condition occurs when temperatures rise 6.5 degrees Celsius or more above normal. If the mercury reaches 47 degrees Celsius or higher in any plain area, it is considered as severe heatwave. 

What do red and orange alerts mean?

The IMD uses four colour alerts to communicate the severity of weather conditions to citizens and authorities. 

Orange Alert (Be Prepared): This indicates that extreme heat conditions are likely. Temperatures will remain between 44-46 degrees Celsius. It alerts authorities to ensure uninterrupted power and water supply, and hospitals to be prepared for heatstroke patients. For the general public, this alert means avoiding afternoon activities unless absolutely necessary.

Red Alert (Take Action): This is the most serious warning issued by the IMD. It simply means that a severe heatwave is at its peak. This condition may persist for more than two or three days. This constitutes a health emergency for people of all ages, especially children, the elderly, and those with pre-existing medical conditions. Authorities strongly advise people to take extreme precautions and remain indoors.

What effect does this extreme heat have on human body?

When the outside temperature exceeds 45 degrees Celsius, the human body's own cooling system (thermoregulation) begins to fail. Our bodies cool themselves through sweating, but extreme drought and hot winds cause the body to lose water rapidly.

Heat exhaustion: Excessive loss of water and salt from the body causes symptoms such as dizziness, severe headache, weakness, excessive sweating and nausea.

Heat stroke: This is the most dangerous and life-threatening condition. When the body's internal temperature reaches 40 degrees Celsius or above, the brain and other vital organs can stop functioning. The patient stops sweating, and the skin becomes red and dry. The person may even faint.