Some type of visual in the room as the participants enter is a good way to signal them that your presentation will be different. It could be an interesting picture or funny quotation on the overhead screen or a nicely done color flipchart page. It could be anything that makes the participants take notice. It will build their anticipation of your presentation.
Uncomfortable people will not listen to you. The unwritten rule is that meeting rooms are always too hot or too cold, so you'll have to do your best.
When setting air-conditioning levels, the room should be cooler than you think it should be. The body heat of the audience will bring the room to the comfort level. Make sure it does, and be ready to make adjustments as you go. If you can't get the right temperature, make sure you acknowledge the audience's discomfort and encourage them to make the best of it. Your care for them will automatically make things a little better.
Tom will pay YOU to read this book...