1. Too hot. Even with full mesh jacket and gloves, and vented helmet, riding with full gear here in the Caribbean takes comittment (and fear of leaving flesh on the pavement).
2. Much too hot. When getting ready to leave a short errand stop, standing in the full tropical sun while getting all the gear on is almost unbearable. Especially when all you wanted to do was get back up to 50mph to create a cooling breeze.
All that said, I don't ride without it, hot or not.