Personally I have never had this issue about getting hot when hand quilting but I do keep a fan blowing on me if I get hot. But this week I got my new Mary Maxim magazine and I saw an adjustable quilting frame that rolls up. Its called a EZ3 Quilting Frame it is 299.99 I found this one also on amazon for 199.
Here are some more that might be cheaper
[h=1]Dritz 28 by 39-Inch Quilters Floor Frame 89.48[/h]