Students stand on the roof of a wooden boat as haze blankets the Musi River while they travel to school in Palembang, on Indonesia's Sumatra island, September 10, 2015. Indonesia is investigating 10 firms over worsening forest fires that have created a blanket of smog over Southeast Asia, threatening them with sanctions if they are found responsible, a government minister said on Tuesday. The thick haze from Indonesia's Sumatra and Kalimantan islands has forced the repeated cancellation of flights in the area and pushed air quality to unhealthy levels in neighbouring Singapore and Malaysia. (Photo by Reuters/Beawiharta)

A scantily-clad brunette is pictured passed out on the pavement. Mayhem hits the streets of Newcastle, UK as clubbers out on the Toon have a little too much to drink as they enjoy the Bank Holiday on August 29, 2016. Photographs take last night show scantily-clad women passed out on the pavement, while boozed-up men were caught arguing with police. (Photo by XposurePhotos.com)

A cat sits in the flooding waters from Hurricane Matthew in downtown Nichols, South Carolina, October 10, 2016. (Photo by Randall Hill/Reuters)

Singers “Elle & The Pocket Belles” attend day 3 “Ladies Day” of the Qatar Goodwood Festival on August 3, 2017 in Chichester, England. (Photo by David Hartley/PA Wire)

Forest guards chase away a rhino that strayed into a residential area after floods forced animals to escape the Kaziranga National park in Nagaon district, in the northeastern state of Assam, August 15, 2017. (Photo by Anuwar Hazarika/Reuters)

Aerial view of pond cypress at Qinglongwan Forest Park near Ningguo, China on November 26, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)

Italy's Mount Etna, Europe's tallest and most active volcano, spews lava as it erupts on the southern island of Sicily, Italy, February 28, 2017. (Photo by Antonio Parrinello/Reuters)

Parade participants during the traditional “Masopust Carnival” festival on February 13, 2018 in Roztoky near Prague, Czech Republic. Known as Masopust (literally, “giving up meat”), the festival was traditionally the last chance to eat and drink in excess before the austerity of Lent. (Photo by Margot Buff/RFE/RL)