I just wanted to point out, so you can think about it, that heat does not in any way cause abusive behavior.
Ask yourself: does heat cause YOU to be abusive? Of course not.
As for being drunk, there is good reason to think that alcohol does not cause abusive behavior either - but, even if actually accept that alcohol can in some causes cause a non-abusive person to engage in abusive behaviors, a non-abusive person will not drink. If, whenever you had a beer, you started engaging in violent behavior and abusing your child, would you ever crack open a beer again?
If these excuses are coming from him, recognize that they are exactly that, excuses. If he excuses his behavior and blames it on external factors, then he is by definition not taking responsibility for his behavior. There can always be a heat wave, or he could have a bad day at work anytime, it could rain, his TV show could be cancelled, his favorite team could lose the game. An abusive person feels free to blame any of those factors - not to mention the most common one, that you drove him to it. A non-abusive person is not going to abuse even if it's hot AND he didn't like the dinner you made AND it was a lousy day at work. And not even if he drinks.
If those excuses are coming from you... think about what you are helping him to avoid responsibility for, and at what cost.
I love this - it is ABSOLUTELY true! (laohaire - I wish someone, anyone, could have told me this growing up - it wouldn't have changed much, but would have made me feel more sane)
Also, echoing the alcohol thing - alcohol doesn't *change* a person - all it may do is lower their inhibitions, so they act out in bigger ways. So, if your husband was typically emotionally or verbally abusive at times, it could escalate when he drinks. In my situation, my dad sobered up and it did absolutely nothing for the abusive situation in my home. But it was like a banner my family loved to wave - "he's not drinking, everything is fine!" It wasn't, not by a long shot. So I'm not inclined to believe that someone who abuses a substance (alcohol) and had proven to be abusive to his family (emotionally and verbally) doesn't have deeper issues at work.