Why in news? Iran recorded a  heat index of 70 degrees Celsius (°C) in the coastal part of the country

Highlights:

What is heat index?

• Heat index, also known as apparent temperature, is a measure of how the temperature feels to humans.
• It considers factors such as air temperature , relative humidity, and dew point
• Relative humidity is an important factor that determines heat index, along with air temperature.

How heat index is calculated?

• A formula to calculate heat index was published by Robert Steadman, a professor of Colorado State University, in 1979 used 14 °C as the dew point in his calculations
• Some countries have developed their own corresponding indices to measure heat index. Ex: Canada uses Humidex

Why it is important to measure the heat index?

• Heat-related illnesses such as cramps, heat exhaustion, and heat stroke become possible from extended exposure to extreme heat
• Excessive heat increases metabolic activity in the body, leading to a drop in blood pressure and oxygen levels with increased sweating this is a condition called hypoxia.
• Heat conditions can alter human behavior, the transmission of diseases, health service delivery, air quality, and critical social infrastructure such as energy, transport, and water.