For years, researchers have looked into a possible relationship between heat and violence. There are conflicting results over whether there is an actual connection between rising anger and rising temperature, but the murder rate constantly increases during the months of July and August, according to the FBI's annual crime report.
Many police chiefs say they put more policemen on the streets when the heat rises. “Calls for service always increase from May, June, July to August，” said New Bedford's Captain Richard Spiriet. “The longer period of time you have the heat, the worse it is. It's just the opposite in the winter time.”
Craig Anderson, a professor and specialist in social psychology at Iowa State University, argues the evidence is clear. “As the temperature goes up, people become more uncomfortable. They become easier to get angry，” he said. “That increases the possibility that a small conflict will be interpreted as more major.” Anderson conducted a couple of studies looking at crime rates over the course of several years within the same area to see when most violent crimes occurred. He found that violent crimes were more likely to occur on hot days and hot months—even hot years had higher violent rates than cold years, according to his research.
Other researches show it is not so much the physical climate, but rather the social climate, that causes increased violence. “During the summer months, people stay up later. They talk with their neighbours. They party with their friends，” said Jack Levin, director of the Brudnick Centre on Violence and Conflict at Northeastern University. “It is more likely to be large numbers of people interacting, and they are more likely to argue.”
Perhaps the realization that there is a link will help spur people in an argument step back and say “Let's cool off.”—both literally(字面上地) and figuratively(比喻地)．

Title	Heat and violence
Theme	Violence possibly has a ________ with heat.
Facts	☆July and August witness the________ increase of murder rate. ☆More policemen are called in with the heat ________． ☆People get angry more ________ as the temperature goes up.
________ of the research	☆Fewer violent crimes occur on ________ days. ☆The ________ climate causes increased violence. ☆People usually go to________ later during the summer months. ☆It is more likely to be ________ when people chat with each other.
Conclusion	________the link will help people in an argument cool off.