Hot Bath
Hot Bath
Hot bath is the most common type of bathing method, which can be done in a bathtub or under a showerhead, and sometimes even in a public bathhouse pool. If conditions permit, taking a hot bath before bedtime every day is highly beneficial for health.
Benefits of Hot Bath
A hot bath can clean the skin and enhance its resistance to disease. The human body has millions of sweat glands on its surface, excreting about 1000mL of sweat daily. During intense physical activity or in summer, sweat production increases significantly. Additionally, sebaceous glands on the skin secrete oily substances that mix with sweat and dust to form dirt. When this dirt accumulates, it may block sweat gland openings and promote bacterial growth, potentially leading to skin diseases such as hyperpigmentation, folliculitis, boils, carbuncles, and impetigo. Taking a hot bath helps remove skin dirt, keeps sweat glands unobstructed, improves skin metabolism, and enhances disease resistance. Clean skin surfaces are slightly acidic, which inhibits bacterial growth. Experiments have shown that one hot bath can eliminate tens of millions to over a hundred million microorganisms from the skin. Hence, hot baths are known as "sterilizing thermal beds."
A hot bath promotes metabolism and relieves fatigue. It increases nervous system excitability, causing blood vessels to dilate, improving circulation and tissue/organ nutrition. At the same time, it reduces muscle tension, relieves muscle spasms, relaxes muscles, and thus eliminates fatigue. Lactic acid levels in the blood indicate fatigue; after labor or exercise, lactic acid increases, causing fatigue sensations. A hot bath accelerates metabolism and speeds up the body’s breakdown of lactic acid.
A hot bath also has therapeutic effects. Clinically, it is used to treat early-stage colds, chronic arthritis, post-fracture recovery, and other chronic conditions. Moreover, hot baths have a calming effect, helping those with poor sleep or frequent insomnia fall asleep more easily and improve sleep quality.
Guidelines for Hot Baths
First, pay attention to water temperature. Bathing water temperature should be adjusted according to individual constitution. Generally, hot bath water temperature should be controlled between 38–42℃. If too hot, excessive heat retention may cause profuse sweating, leading to depletion of body fluids and qi. If exposed to cold wind afterward, illness is likely. If too cold, sudden exposure to cold can trigger disease. As stated in *Qianjin Yaofang*: "Bathing must not be too hot nor too cold, or it will cause myriad ailments."
Second, control duration. Bathing time should not be too long. Staying in the bathroom for extended periods may lead to excessive energy expenditure and insufficient oxygen supply, potentially triggering angina or elevated blood pressure. Those with coronary heart disease, hypertension, or cerebral vascular sclerosis should especially be cautious—avoid prolonged soaking baths and prefer showers to prevent cerebrovascular accidents or myocardial infarction.
Third, avoid bathing when extremely hungry or full. As the saying goes: "Empty stomach causes dizziness and shortness of breath." When hungry, body heat decreases and blood glucose drops. Bathing consumes significant energy, primarily replenished by glucose oxidation in the blood. Thus, bathing while hungry may lead to dizziness, blurred vision, or even fainting, commonly known as "fainting from hunger." Conversely, bathing immediately after a heavy meal causes surface blood vessels to dilate due to hot water stimulation, diverting blood flow from internal organs like the gastrointestinal tract to the skin, resulting in inadequate blood supply and impaired digestive function, increasing risk of indigestion.