I plan on using the Heatsheet Emergency Bivvy in all of the kits I currently have a Thermo-Lite Bivvy in and a few of my kits that I currently have a Heatsheet in. The Heatsheet Emergency Bivvy is close to a quarter the size of the Thermo-Lite Bivvy but is bulkier and takes up a little more then twice the space of the standard 2-Person Heatsheet.
_________________________
"Trust in God --and press-check. You cannot ignore danger and call it faith." -Duke