Medics or volunteers wearing the white hazmat suit are nicknamed Big White. It is part of the secondary protection gear for those who make close contact with suspected or at-risk groups, or stay indoors with them for a long time.

Secondary protection gear includes six items: disposable hat, N95/KN95 or medical mask, goggles or facial screen, hazmat suit, gloves, shoe covers or work shoes.

Jiang Ning, 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 working.

1. Follow orders on how to wear the items so that they can be safely taken off in order.

2. Put on the facial mask first, followed by the hazmat suit and shoe covers and finally the gloves.

3. Check the details, such as hair must be completely inside the hat; gloves must fully wrap the cuffs; shoe covers must contain the cuffs of hazmat trousers; and facial screen must cover the jaw completely.

4. All personal protective equipment must be changed within four hours. If contaminated or damaged, they must be promptly replaced.

5. At least two volunteers must work together to remind each other. Never work alone in secondary protection.

6. First, take off the gloves, which are the dirtiest, followed by facial screen or goggles. Hazmat suit and shoe covers must be removed together. Then remove the hat and mask and put on a new mask. Clean and disinfect hands after taking off each piece.

7. Move slowly and gently when taking off the protective items. The surface must be wrapped inside. If several people are taking off the protection gear together, they must keep a distance of at least 2 meters and follow all the steps simultaneously.