2, strengthen the body: moderate sun exposure can enhance the body’s resistance to viruses, germs and other pathogens, and increase the vitality of human phagocytes; 3, calcium: human contact with sunlight can promote the synthesis of vitamin D in the skin, which is conducive to the absorption of calcium and phosphorus, and the deposition of calcium in the bones, which is beneficial for the prevention and relief of osteoporosis and fractures, and also helps children’s height growth; 4, promote The infrared rays in the sunlight can enter the subcutaneous tissue and play a heating effect, which can promote vasodilation, accelerate blood circulation and increase metabolism, especially for pregnant women and other inactive people; 5, relieve stress: moderate sun exposure can relieve the body’s tension, improve the discomfort caused by depressed mood and excessive stress. But when sunbathing should also pay attention to, choose more morning, afternoon, and avoid sunbathing in the middle of the summer when the sun is strongest, to prevent heatstroke and sunburn.