Cataratas del Niágara, bajo cero

NIAGARA FALLS, ONTARIO, CANADA – FEBRUARY 20: Sightseers take pictures of a nearly frozen Niagara Falls on February, 20 2015 in Niagara Falls, Ontario, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, CANADA- FEBRUARY 20: The American side of the Niagara Falls are almost completely frozen after a prolonged period of extreme cold on February, 20 2015 in Niagara Falls, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, CANADA- FEBRUARY 20: The American side of the Niagara Falls are almost completely frozen after a prolonged period of extreme cold on February, 20 2015 in Niagara Falls, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, CANADA- FEBRUARY 20: A sightseer takes a picture of a nearly frozen Niagara Falls on February, 20 2015 in Niagara Falls, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, ONTARIO, CANADA- FEBRUARY 20: The American side of the Niagara Falls are almost completely frozen after a prolonged period of extreme cold on February, 20 2015 in Niagara Falls,Ontario Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, ONTARIO, CANADA- FEBRUARY 20: A frozen cliff face on the American side of the Niagara Falls is seen on February, 20 2015 in Niagara Falls,Ontario Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, ONTARIO, CANADA- FEBRUARY 20: The American side of the Niagara Falls are almost completely frozen after a prolonged period of extreme cold on February, 20 2015 in Niagara Falls,Ontario Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS,ONTARIO, CANADA- FEBRUARY 20: The American side of the Niagara Falls are almost completely frozen after a prolonged period of extreme cold on February, 20 2015 in Niagara Falls, Ontario, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, ONTARIO, CANADA – FEBRUARY 20: Sightseers look at a nearly frozen Niagara Falls on February, 20 2015 in Niagara Falls, Ontario, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP

NIAGARA FALLS, ONTARIO, CANADA – FEBRUARY 20: Sightseers take pictures of a nearly frozen Niagara Falls on February, 20 2015 in Niagara Falls, Ontario, Canada. Much of the United States and Canada are experiencing unusually cold weather with record low temperatures and the wind chill factors making it feel well below freezing. Aaron Vincent Elkaim/Getty Images/AFP