If you need to evacuate your car and hike out having shelter is very important.  A good shelter can be the difference between life and death. With the size and cost constraints it is not practical to carry a regular tent. Space blankets and Bivvy sacks can help in this area.  I recommend that you carry the Adventure Medical Kits Heatsheets® Emergency Bivvy as well as a normal space blanket.  The Adventure Medical Kits Heatsheets® Emergency Blanket is very good options for your space blanket.

Both of the Adventure Medical Kits Heatsheets® are made from polyethylene material. Polyethylene has been shown to be more durable than the Mylar material that most space blankets are made from. During multi day use durability is very important.

Having both the emergency blanket and bivvy sack increases the number of options available when you need to shelter. The primary insulating shelter is the bivvy sack. The bivvy sack reflects 90% of your radiant body heat back. However, you still need to try to create a bed of insulating materials to lay on. If all that is between you and a rock or cold ground is the bivvy sack and the clothes you are wearing, your body heat will tend to be wicked right out of you.

The space blanket has a number of key uses:

• A second layer with the bivvy sack.
• Combined with some rope the blanket can act as a small rain or snow shelter.
• During the day the blanket can be laid out on the ground as a signal to planes and helicopters.
• The Blanket can also be modified and used as a rain or snow shell.

During any emergency, flexibility is very important. Having both the bivvy and blanket greatly increases your shelter options while taking up very little additional space in your pack.