July 19th News: According to reports， the “Sanfu” period， a segment of the hottest days of the year in China， officially begins on July 20th. Many regions across the country are entering a sustained period of high temperatures.
Experts note that from 2015 to 2024， the “Sanfu” period consistently lasted for 40 days. This year， however， marks a deviation from this trend， with the “Sanfu” period set to be 30 days in duration. This breaks a decade-long record of extended hot weather.
The dates for “Sanfu” are determined by an ancient Chinese calendrical method known as the “Heavenly Stems and Earthly Branches” (干支纪日法). Specifically， the first “Fu” (初伏) begins on the third Geng day after the Summer Solstice， the second “Fu” (中伏) on the fourth Geng day， and the last “Fu” (末伏) on the first Geng day after the beginning of Autumn. Together， these periods constitute “Sanfu.” The shift to a shorter “Sanfu” this year might be attributed to subtle variations in the astronomical timing of the Summer Solstice and the subsequent Geng days， reflecting the complex calculations involved in traditional Chinese calendrics.
During the intense heat of “Sanfu，” many households opt for prolonged use of air conditioning. It is advisable to set indoor temperatures no lower than 25 degrees Celsius and to avoid directing the air directly at the shoulders and back. If the temperature cannot be adjusted manually， a shawl can be used for covering. Taking a warm bath in the evening is also recommended to help the body regulate its temperature.
High temperatures accelerate dehydration. Many people tend to drink large amounts of water quickly. However， rapid water intake can lead to a quick absorption into the bloodstream， diluting the blood and increasing blood volume. For individuals with coronary heart disease， this can trigger symptoms like chest tightness and shortness of breath. Therefore， it is crucial to drink water slowly and in small， frequent amounts， approximately 100-150 ml at a time， to facilitate better absorption. Furthermore， avoiding excessively cold water is advisable; lukewarm water above 10 degrees Celsius is generally considered best for the body.
Additionally， due to the early sunrise in summer， many people engage in morning exercises in parks before 6 AM. Research indicates that in the early morning hours before 6 AM， pollutants such as nitrogen oxides and hydrocarbons from vehicle emissions and other sources tend to accumulate in the air， reaching peak levels during this time. Inhaling this polluted air can have adverse effects on health. Consequently， it is recommended that summer morning exercise should not commence before 6 AM to avoid exposure to higher concentrations of air pollutants.
