As Jose Cleiton and Brandao Amilton ride their horses into the vastness of the Pantanal grassy wetlands of Brazil, a wall of smoke towers from the horizon far into the sky above.

The worst of the dry season is still far off, but already these Brazilian wetlands are so dry that wildfires are surging.

The number of Pantanal fires so far this year has jumped tenfold from the same period last year according to Brazil's National Institute of Space Research (INPE).

"It's hard to breathe. It's hard for newborn children. The heat gets stronger and stronger," said Amilton, a local fishing guide. "The Pantanal is already hot and it gets hotter, drier, with smoke, the weather gets very bad."

The men guide cattle across the flood plain, hoping for a better chance of survival. "The way the fire is coming, it could surround them and burn them to death," said Cleiton, a farmer.

The Pantanal wetlands, roughly 10 times the size of the Florida everglades, are home to jaguars, tapirs, caimans and giant anteaters. Weak rains since late last year have disrupted the usual seasonal flooding, leaving more of the region vulnerable to fires.

As the region approaches the riskiest season for wildfires, which usually peak in September, experts are warning that the blazes so far this year are worse than the start of a record 2020, when a third of the Pantanal burned.

More than 3,400 square km (1,315 sq miles) of the Pantanal have burned from Jan. 1 to June 9, the highest level on record, according to the Federal University of Rio de Janeiro's satellite monitoring program, with data going back to 2012.