Head space is not an issue. Every time you move your beer you knock the CO2 out of suspension and it blankets the beer to protect it.
Once it's fermented, temperatures are not as much of a problem. Next time, get a large tub that your primary can fit in. Fill the tub with water and put a to t shirt or towel around your primary to wick the water up. It will help keep your temperature of your primary down during the summer.
Batch 1 Brewing
The American Revolution would never have happened with gun control.