As record-breaking heat waves become more common around the world, including across tropical destinations like Bali, many people instinctively reach for air conditioning. But long before AC existed, communities living in some of the world’s hottest climates developed remarkably effective ways to stay cool, and science suggests many of those methods still work today.
With temperatures climbing across Europe, Asia, and other parts of the globe, researchers are revisiting centuries-old cooling techniques that require little electricity but rely instead on physics, architecture, clothing, and human biology.
According to a report highlighted by The New York Times, several traditional practices have now been supported by modern scientific research.
1. Splash Water on Streets to Cool the Air
In Japan, the centuries-old tradition of uchimizu involves sprinkling water on sidewalks, roads, and building entrances during hot weather.
Originally performed as a gesture of hospitality before tea ceremonies, the practice also creates evaporative cooling.
A study published in the journal Water found that lightly spraying water onto paved surfaces can reduce air temperatures near ground level by as much as 5.5 degrees Celsius (10 degrees Fahrenheit) under the right conditions.
Experts say the cooling effect becomes even stronger when entire neighborhoods participate, lowering surrounding temperatures without consuming large amounts of electricity.
For dense urban areas increasingly affected by heat islands, the concept is attracting renewed attention.
2. Wet Vetiver Curtains Were Nature’s Air Conditioner
Before mechanical cooling became available, families across parts of India relied on curtains made from vetiver grass roots, also known as fragrant roots.
The woven curtains were soaked with water and hung across doors and windows facing the breeze.
As hot air passed through the damp fibers, evaporation absorbed heat, naturally cooling the air before it entered the home. The fragrant roots also released a pleasant earthy scent.
Today, similar evaporative cooling principles are inspiring energy-efficient cooling systems for modern data centers seeking alternatives to conventional air conditioning.
3. Loose Black Clothing Can Actually Keep You Cooler
Wearing black in hot weather sounds counterintuitive.
Yet for centuries, people across the Middle East and North Africa have worn loose-fitting black robes while living in desert climates.
Research published in the journal Nature found that the loose design is the key.
Although black fabric absorbs more solar radiation, the heated air inside the garment rises and escapes through the top, pulling cooler air upward from below. This natural airflow helps remove heat before it reaches the skin.
The study concluded that the additional heat absorbed by the fabric dissipates before significantly warming the wearer.
Lightweight textured fabrics such as seersucker cotton also help improve airflow by preventing fabric from sticking to sweaty skin.
4. Spicy Food and Unsweetened Tea Help the Body Cool Itself
Many of the world’s hottest countries, including India, Thailand, and Mexico, are famous for spicy cuisine, and there is a physiological reason why.
Chili peppers contain capsaicin, a compound that stimulates heat receptors in the mouth. The brain interprets this as rising body temperature and responds by increasing sweating and widening blood vessels, helping the body release heat through evaporation.
Meanwhile, experts say sugary soft drinks are less helpful during extreme heat.
Digesting large amounts of sugar generates additional internal heat and may reduce the body’s natural cooling response.
Across many Asian countries, unsweetened teas made from ingredients such as barley remain popular because they help maintain hydration while supporting healthy blood circulation.
Alcohol, including beer, is also discouraged during heat waves because it promotes dehydration and interferes with the body’s ability to regulate temperature.
5. The Return of the Afternoon Siesta
The traditional afternoon nap, or siesta, has long been part of daily life in countries such as Spain, Greece, and Italy.
Scientists say the practice makes sense.
The human body naturally generates heat through movement and metabolism. Avoiding strenuous activity during the hottest part of the day reduces the risk of heat exhaustion and heat stroke.
As European summers become increasingly intense, some public health experts have begun encouraging employers to reconsider midday breaks.
In 2023, Germany’s National Association of Statutory Health Insurance Physicians even suggested adopting work schedules similar to southern European countries during periods of extreme heat.
What This Means for Bali Residents and Visitors
For people living in or visiting Bali, where high temperatures and humidity are a year-round reality, these traditional techniques offer practical ways to stay comfortable while reducing dependence on air conditioning.
Simple habits such as improving ventilation, avoiding strenuous activity during the hottest hours, staying hydrated with low-sugar drinks, and choosing breathable clothing can help lower the risk of heat-related illness.
As climate change continues to push temperatures higher across much of the world, some of humanity’s oldest cooling traditions may once again become some of its smartest solutions.
