Well, it depends on whether you are dayhiking and only considering a shelter in the event of an emergency, or if you are planning to overnight it.

Because of my size and the fact that I usually have at least one person with me anymore, I take a three man 3 season tent along on overnight excursions. There are a whole lot of these out on the market, so I recommend research for picking out what suits you. I don't backpack much in winter, though elk season can get pretty rough. If I plan to use my tent for a satellite camp, then I will throw in a 10' x 10' tarp and look for a place to rig a secure cover to avoid overloading the tent frame if it snow loads. I tend to look for relatively inexpensive and lighter models.

For day hikes or as a backup for overnighters, I will pack the bivvy bag along, and/or a couple tarps. Occasionally I will forego even these and just keep the plastic garbage bags I always hike with. It depends on how arduous the hike and what the ambient conditions are.

This is what I use. The GoLite lair 2. The weight with stakes included in just over 1lb.

I use a military poncho. Works well. I am going to try using a hammock this year, so, the poncho may be a bit redundent. But, for a simple, quick setup, nothing beats the good ole poncho! I've perfected setting it up, & get get it down in about a minute. not too bad...I am passing this knowledge on to my nephew tomorrow.

A Hilleberg Tarp 10 XP Sil-Polyester or Integral Designs sil-nylon tarp, a cheap waterproof groundsheet and a Thermarest mat.

How many pounds do you carry for a day hike SBRaider?
Thanks,
Bryan

Mountain Hardwear PCT 2 Tent Or Coghlan's Tube tent

I carry an AMK Heatsheet. Sufficient for a night or two. Folded, it's slightly longer and heavier than a cheap survival blanket. I recently added a large waistpack to my bag arsenal so i'm not willing to carry anything bigger (bivvy) because of this. I move the Heatsheet from bag to bag depending on the activity.

I have everything I need to start a lot of fires as well.

So I read all of these, and I'm wondering if anyone can explain the differences between:
Thermo-Lite 2.0 Bivouac Sac
Thermo-Lite Single Bivy Sack
Heatsheets Emergency Bivvy

They're all made by AMK, but range from $14 to $32. I can't see a big difference in the descriptions of them, so any help is appreciated!

Heatsheet bivvys are not much bigger than Heatsheet blankets, if they are at all...

in answer to my enquiry, I got this mail from Aeromedix :

"The dimension on the Thermo-Lite Bivvy Sack when stored are approx. 6"x3.5"

The difference between the Thermo Lite Bivvy and Heatsheet Bivvy is mainly the material. The Thermo Lite Bivvy is a much more heavy duty item for more serious conditions."