This picture taken on March 1, 2016 shows a man running a mobile pig mating service and waiting outside a customer's home with his male pig in a cage pulled behind his motorcycle in the northern province of Bac Ninh. (Photo by Hoang Dinh Nam/AFP Photo)

Pupils of the Dao ethnic tribe return home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

Thousands of bright yellow silkworm cocoons are dried in huge clay bowls in the village of Hong Ly, northern Vietnam in July 2022. Silk fibres are produced by silkworms when they spin themselves into a cocoon on their journey to becoming a silkmoth. The ultra-soft fibres are harvested from the cocoon in their raw state by being boiled in hot water. (Photo by Prabu Mohan/Solent News)

This photograph taken on June 8, 2021 shows a street vendor walking past narrow residential houses, known as “nha ong” in Vietnamese or “tube houses”, in an urban area of Hanoi. (Photo by Manan Vatsyayana/AFP Photo)

The colourful process of salt harvesting is captured at the Hon Khoi Salt Fields in Nha Trang, Vietnam in December 2022. (Photo by Hilton Chen/Solent News & Photo Agency)

A Sphynx cat is held by its owner at the WCF International Cat Show in Hanoi, Vietnam, 02 April 2023. The two-day event opened on 01 April at the Van Ho Exhibition Centre in Hanoi. (Photo by Luong Thai Linh/EPA)

People wear clothing to protect them from the heat while riding along a street in Hanoi, Vietnam, 24 April 2019. North and central Vietnam was recently affected by extreme hot weather, with the highest temperatures reaching over 40 degrees Celcius, according to the National Centre for Hydro-meteorological Forecasting. (Photo by Luong Thai Linh/EPA/EFE)

A labourer packs incense in preparation for Tet, the traditional Vietnamese lunar new year, in Hong Chau village, outside Hanoi January 29, 2015. Tet is from February 14 till 24. (Photo by Reuters/Kham)