Is it Heat Wave, Heat-wave or Heatwave?

Is it a “heat wave”… or a “heat-wave”… or a “heatwave”?

I’m too hot and cranky to even care how it is spelt / spelled. 

We just know it’s extremely hot right now and we have to do the best we can to stay cool. 

Take a look at this list of items under the category STAY COOL that will help you tolerate this “wave of heat”.   

PS.  Is it forest fire or wildfire?

That is a question for another day.