Could the current temperature be deadly? Exploring the Heat Index and its mechanisms
Produced by: Tarun Mishra Designed by: Manoj Kumar
Record-Breaking Temperatures in Delhi
The India Meteorological Department (IMD) reported an unprecedented temperature of 52.3°C in Delhi, with Mungeshpur, a suburb, also recording its highest temperature ever, exceeding 50°C for the first time. This extreme heat event reflects a broader trend of rising temperatures across the region.
Heat Wave Forecast
The IMD has issued a severe heat wave forecast, predicting “heat wave to severe heat wave conditions” in various parts of Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, Rajasthan, Jammu & Kashmir, and Himachal Pradesh. Warm nighttime temperatures offer little respite from the daytime heat.
Understanding the Heat Index
The heat index, or apparent temperature, accounts for the combined effect of air temperature and relative humidity on how hot it feels to the human body. Higher humidity reduces the rate of perspiration and evaporation, making the body feel warmer.
Effect of Humidity on Comfort
In humid conditions, the body’s ability to cool itself through perspiration is hindered, leading to increased discomfort. Conversely, lower humidity levels facilitate more effective perspiration and cooling, resulting in a sensation of cooler temperatures.
Calculation of Heat Index
The heat index is determined by combining air temperature and relative humidity. Higher temperatures and humidity levels yield higher heat index values, indicating increased discomfort and potential health risks associated with heat exposure.
Impact of Sun Exposure
Direct sunlight can further elevate the heat index by up to 15°F compared to shady locations. Heat index values exceeding 103°F can pose significant health risks, particularly with prolonged exposure and physical activity in the heat.
Heat-Related Health Disorders
Exposure to high heat index values can lead to dangerous heat disorders, including heat exhaustion, heat stroke, and other heat-related illnesses. Individuals are advised to take precautions to prevent heat-related health issues during extreme heat events.
Regional Variations in Heat Index
While high temperatures are common in certain regions, low relative humidity values can mitigate the impact of heat index values. However, dangerous heat index values can still occur, particularly in areas with high humidity levels.
Preventive Measures
Understanding the heat index and its impact on the body is crucial for implementing preventive measures during heatwaves. Staying hydrated, seeking shade, and avoiding strenuous activity during peak heat hours can help mitigate the risk of heat-related illnesses and fatalities.