Medics or volunteers wearing the white hazmat suit in the campaign against COVID-19 are nicknamed Big White. It is part of the secondary protection gear for those who have to make close contact with suspected or at-risk groups, or stay indoors with them for a long time.The secondary protection gear mainly includes six items: disposable hat, N95/KN95 or medical mask, goggles or facial screen, medical hazmat suit, gloves, shoe covers or work shoes.Jiang Ning, an associate chief physician with the Shanghai Center of Disease Control and Prevention, said that wearing and taking off the hazmat suit involves a lot of professional skills, so volunteers must receive special training before they start working.