Heatwave alert: Are high nighttime temperatures more harmful to your health than daytime temperatures?

Dr Chaitanya H R , senior consultant physician at Athreya Hospital, Bengaluru remarks, “High nighttime temperatures exacerbate the health impacts of heatwaves by not allowing the body to cool down after the day’s heat.” 

According to research from the Centers for Disease Control and Prevention (CDC), he says, prolonged exposure to high temperatures without adequate nighttime relief increases the risk of heat-related illnesses, such as heat exhaustion and heat stroke. This continuous exposure can strain the cardiovascular system and lead to dehydration.

Physiological effects on the human body

When temperatures do not drop significantly overnight, Dr Chaitanya explains that the human body cannot recover from the daytime heat stress. This can lead to:

Increased Core Body Temperature: The body’s cooling mechanisms, such as sweating, are less effective, leading to a rise in core temperature.

Urban heat islands (UHIs) contribute to higher nighttime temperatures to a great extent. (Source: Freepik)

Dehydration: Persistent sweating without adequate fluid replacement causes dehydration, impacting bodily functions.

Strain on the Heart: Elevated temperatures cause the heart to work harder to pump blood to the skin for cooling, increasing the risk of cardiovascular events.

Role of urban heat islands

Urban heat islands (UHIs) contribute to higher nighttime temperatures to a great extent. Cities, with their concrete, asphalt, and reduced vegetation, absorb and retain heat, releasing it slowly overnight, which can be very harmful. 

“According to the Environmental Protection Agency (EPA), this phenomenon increases the ambient temperature in urban areas, exacerbating the effects of heatwaves. Long-term implications include the need for urban planning strategies such as increasing green spaces, implementing cool roofs, and enhancing urban forestry to mitigate these effects,” informs Dr Chaitanya.

How you can get relief from rising nighttime temperatures

Dealing with high nighttime temperatures can be challenging, but there are several strategies that can help you stay cool and comfortable, Dr Chaitanya assures. Some of these include:

*Opt for lightweight, breathable fabrics like cotton or bamboo for sheets and pillowcases. These materials wick away moisture and improve airflow.

*Before going to bed, place ice packs or cooling gel pads under your pillow or sheets. This can help lower the bed’s temperature.

*Drink plenty of water throughout the day and before bed. Hydration helps your body regulate its temperature more effectively.

*Eat light, easily digestible meals in the evening. Heavy meals can increase your body’s metabolic rate and generate more heat.

*Taking a cold shower before bed can lower your body temperature and help you feel cooler.

*Use blackout curtains or shades to block out sunlight during the day, reducing indoor temperatures.

*Open windows during the cooler parts of the day, such as early morning or late evening, to let cooler air in. Use cross-ventilation techniques to enhance airflow through the house.

*Use indoor plants or plant trees in your garden as these can provide shade and reduce the amount of heat entering your home.