In general, more expensive helmets have bigger vents/better air flow and are lighter. Based on the Aspire's price, it's not the best for very hot weather.

But before talking about helmets -- managing the heat is more than venting your head. Make sure you're taking steps to cool yourself from head to toe.

My LBS carries that Catlike helmet, and I rejected it because it's too expensive for me. I have a Bell Volt and a Giro Pneumo.

I don't wear anything under the helmet, but I know people who wear lightweight caps under helmets, either to absorb sweat or help with wicking/cooling. I think Muirenn likes the Zoot Icefill caps, and she has other summer clothes she likes for heat and humidity.