"Record US heatwave blamed for spike in murders"

Surely it has long been recognized that there are fewer murders during winters than summers, but are there even more murders when there are heat waves? There is not a lot of data mentioned here, but it would be worth accounting for this in monthly crime regressions.  From the UK Telegraph: 

Temperatures rose beyond 104F (40C) in cities from Kentucky to Pennsylvania, with a record 107F (41.7C) registered briefly in Washington DC.
Some 16 murders have been recorded in New York City over the past five days, roughly twice the average rate. One city councilman described the city as a "brewing cauldron". . . .