LYNN-It happens about this time every year. With the drop in temperatures comes a slew of homeless people seeking warmth.And in the past few days, several local homeless have discovered that getting warm isn’t so easy.In fact, four people were arrested on West Green Street Monday night after they allegedly broke into a vacant apartment building seeking relief as temperatures dipped into the low 20s.Their arrests came less than three hours after firefighters in Peabody extinguished a two-alarm fire at an abandoned gas station that was speculated to have started by homeless trying to keep warm.On Saturday, a homeless man was found burned to death in a pickup truck in a Lynnway parking lot. Authorities said he started a fire in the cab to keep warm.Police were called to 21 West Green St. at 10:45 p.m. Monday after a neighbor noticed two women and two men breaking down the front door and entering the building.When officers arrived, they found the door was unlocked and had been forced open. Officers then came upon another door that had been forced open, which led to the second floor apartment.The police officers then smelled smoke and entered the apartment where they discovered four people. They were ordered to put their hands into the air.After the suspects came out of the apartment and were pat frisked, police discovered that someone was cooking food on the stove and started a small fire. An officer extinguished the flames.The four people, identified as Danielle Bulger, 31, of 117 North Common St., Julio A. Nunez, 33 and Carmen Pena, 32, both of 10 Henry Ave. #1 and Samuel Ortiz, 26, homeless, were arrested and charged with breaking and entering at nighttime with intent to commit a felony.According to a police report, Nunez told officers that all four people were homeless and they were just trying to get out of the cold.