Some of the residents had to be rescued from the second floor of their burning home as flames spread all around them.
The first fire, which went to three alarms, broke out on the top floor of an apartment building on Riverdale Avenue around 6:45 p.m. and left two people seriously injured.
Two men were pulled from the building suffering from burns and smoke inhalation. They were rushed to Jacobi Medical Center in the Bronx in critical but stable condition.
Crews were able to contain the flames and keep them from spreading throughout the entire building.
About 50 people were forced out of their homes, and the Red Cross was aiding the victims.
The second fire was a four-alarm blaze that began around 9:30 p.m. at a multi-family home on Beech Street.
Arriving firefighters found flames shooting out the back of the four-story home and several residents hanging out of upper floor windows.
"We had fire blowing out the rear of the structure and people in the windows in the front who could not exit the building," Assistant Fire Chief Eric Dronzer said. "So we laddered the building with ground ladders and our tower ladder, and we were able to rescue the people from the windows."
The harsh icy conditions caused hydrants and fire hoses to freeze.
No one was seriously hurt, but nine firefighters suffered minor injuries and exhaustion after officials said many of them had also responded to the earlier fire.
Around 20 people were displaced.