Scifi movie identifying help? ?

I remember watching a movie that was set in los angeles and there was a massive heat wave. People started looting and these tow truck drivers were sitting around an air conditioner positioned on a chair with stings waving out the ac vent. They stole money from a bank and went into the dry sewer system. But then the sewers were flooded and the heat wave was over. Any ideas what this movie is? I've been trying to find out for years. And no its not called heat wave. Haha