Context: 

Heatwaves are a significant public health issue, as evidence by the recent heatwave in Uttar Pradesh and Bihar.

• For Example: In Balia, a district in Uttar Pradesh, there were a high number of deaths attributed to the heatwave.

About Heat Waves:

• Heat Waves:  Heat waves are defined as prolonged episodes of extreme temperature over any region.  
• The IMD considers the following factors when determining a heatwave:
  • Temperature Thresholds: 
    • Plains: A heatwave is declared in the plains when the maximum temperature reaches at least 40 degrees Celsius. 
    • Coast: Along the coast, a heatwave is declared when the maximum temperature reaches at least 37 degrees Celsius. 
    • Hilly Regions: In hilly regions, a heatwave is declared when the maximum temperature reaches at least 30 degrees Celsius.
  • Temperature Deviations from Normal: Alternatively, a heatwave is declared when the maximum temperature rises by between 4.5 degrees Celsius and 6.4 degrees Celsius above the normal temperature.
  • Severe Heatwave: If the maximum temperature departs from the normal by more than 6.4 degrees Celsius, a severe heatwave is declared. This indicates an exceptionally intense and potentially dangerous heat event.
  • Extreme Heat: Additionally, a heatwave condition arises when an area records a maximum temperature of more than 45 degrees Celsius and up to 47 degrees Celsius on any given day. 

Formation of Heat Waves:  

• A heatwave is formed when static high pressure is generated in the upper atmosphere over a region for several days up to several weeks.  
• This static high pressure generates a hot mass of air, which is stagnant for many days and weeks, which results in the trapping of more heat that also reduces the convection currents.  
• The high-pressure acts as a barrier and forces the mass of air to sink to the surface of the land that preventing heat from rising.  
• This hot mass of air accumulates only heat and humidity without any trace of precipitation that causes abnormally high temperatures. 

Impact of Heatwaves:

• Health Impacts: 
  • The health impacts of Heat Waves 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°C i.e.,102°F.  
    • Heat Exhaustion: Fatigue, weakness, dizziness, headache, nausea, vomiting, muscle cramps and sweating.  
    • Heat Stroke: Body temperatures of 40°C i.e., 104°F or more along with delirium, seizures or coma. This is a potential fatal condition. 

• • Factors Influencing Heatwave Deaths:
    • Bad public infrastructure and social security. 
    • Contaminated water, or because the local people could not cool themselves. 
    • Heat’s deadliness depends on an individual’s general well-being, acclimatization, physical exertion, comorbidities, location, relative humidity, and extent of heat exposure.
    • Heat becomes deadly when bodies can’t shed it as fast as it accumulates, often influenced by poor living conditions and societal norms.

• Environmental Impact: Heatwaves can have detrimental effects on the environment, including increased evaporation and drying of water bodies, depletion of water resources, and heat stress on plant and animal species. 
  • They can disrupt ecosystems, damage crops, and contribute to wildfires, exacerbating the overall impact of climate change.
• Economic Consequences: Heatwaves can impose substantial economic burdens on communities and countries. 
  • They can disrupt agricultural activities, leading to reduced crop yields and financial losses for farmers. 
  • Additionally, heatwaves can strain energy systems as people rely heavily on cooling systems, resulting in increased energy demands and potential blackouts.
• Impacts on Infrastructure: Heatwaves can strain infrastructure systems, such as power grids, transportation networks, and water supply systems. 
  • Increased energy consumption for cooling can overload power grids, leading to power outages.

To mitigate the problems of heatwaves, several measures can be implemented:

• Increase Green Spaces: Promote greening initiatives in urban areas by planting more trees and creating urban forests. 
• Improve Urban Design: Design urban layouts that enhance natural ventilation and reduce the urban heat island effect. 
• Expand Wetlands and Restore Water Bodies: Expand wetlands and restore ponds, lakes, and water bodies to improve ecological functioning and reduce urban heat.
• Waste Management: Implement effective waste management practices, including waste segregation and solid waste management at the source. 
  • Reduce the size of landfills to minimize methane production and the associated heat exacerbation.
• Improve Forecasting and Planning: Improve forecasting capabilities to include heat trends and their impact on food production, storage, and sale. 
• Adaptation Measures: Institute structural infrastructure measures to help communities adapt to heatwave conditions. 
  • This may include measures to protect marginalized farmers and urban migrants from the adverse effects of heatwaves.

Way Forward:  

• Establish Early Warning System and Inter-Agency Coordination to alert residents on predicted high and extreme temperatures.  
• Identifying heat hot spots through appropriate tracking of meteorological data and promoting timely development and implementation of local Heat Action Plans.  
• Amenities for Heatwave Relief: Amenities that can help include access to drinking water, indoor ventilation, health care, regular work breaks, and protections against wage loss. 
• Registration and Cause Assignment of Heat-related Deaths: Need to register all heat-related deaths, assign the cause, ensure the medical certificates of the cause of death (MCCDs) follow the proper codes of the most recent revision of the International Statistical Classification of Diseases and Related Health Problems, and issue them. 
• The Office of the Registrar General should compile and release MCCD data every year to facilitate independent research and policy input and to prevent time-wasting disputes over official versus actual figures. 

News Source: The Indian Express