OK. Bear with me. I'm tasked with getting rid of all the boxes and wrapping paper from the old Griswold family Christmas. I'm outside last night down by the water with a fire in the fire pit. It's about 25 degrees plus there's a nice breeze coming off the water. So whatever's closest to the flames stays warm, while everything else is cold. I decided to actually practice using a heat shield to see if it made a difference, and decided to use only what I had on me at the time. Now given that the fire was already burning with Scooby Doo wrapping paper, I recognize this wasn't exactly a perfect replica of a survival situation, so please keep the wise cracks to a minimum.

So here's what I did:

Using a Petzel Zipka and a Cold Steel Mini-Hunter, I located and cut down two small saplings about an inch in diameter and about four feet long. I sharpened one end of each and drove it into the ground about 3 feet from the fire and about four feet apart from each other. I then took out the emergency space blanket in my kit (I carry a heavily loaded PSK in a Maxpedition Vulcan when I am at the lake or on the water), and the amall roll of duct tape. I wrapped one edge of the blanket around each pole and secured it with a small strip of duct tape at the top and bottom. I left the resulting shield at about a 90 degree vertical, and sat between it and the fire.

Obviously, there was a noticeable improvement in the effectiveness of the fire, but to be honest I had no idea what I was doing. I had read that reflective material could be used as a heat shield, so this was a best guess.

So, my request to the group is for a merciless critique. Given the most common contents of a PSK, should I have used aluminum foil instead? Is it better for this purpose? What's the best way to craft the shield? Should it be at more of a 45 degree angle? Are the distances from the fire right?

While I'm on the subject, any other "exercises" like this that anyone has tried, or that would be good practice? Obviously, fire starting - but any others?

Thanks in advance for any feedback, and have a Happy New Year.

Rod

The only time I've build a heat shield was in Nov year ago when I went kayaking.

I used an old camping table that I fliped over. Now I knew it is going to be below freezing overnight and few of us wanted to hang out in front of the fire without staying too close to the flames. So... My situation was kind of similar to yours as far as the water is concerned. First of all we couldnt form a 90 degree angle on the table top due to a bench being attached to it so our reflective surface was at about 60-70 degrees which we figured out is better because it would circulate the air. So we tried two things:

First is that we put the table on the side of the fire (6 feet away) that was away from the water. Small breeze was going over the fire and hiting the heat shield that reflected the heat back at us and whoever was at that side of the fire was very warm. Whoever was on the water side was still freezing from the water. We fixed that by laying down a kayak accross and that kind of trapped the heat. Hey even few degrees made a difference.

Second was that we positioned the barrier between us and water trying to kill the breeze and cold wind. That worked fine and gave us kind of even heat all around. But again our backs were little cold (exposed people complained less thou) but people with their backs to the shield said that heat is not as great as in the first trail.

If it was me alone and I had to reflect the heat I would have used the first method and use breeze as a free fan.

Now how do I know that our stuff worked? Well water that was left outside the parameter of the fire was frozen in the morning. Water in the cups that was left by the heat shield was in its normal liquid state. Like I said couple degree difference was not much but enough.

Now I wouldn't use my space blanket for the shield but look for other stuff such as wood, branches, scrap, whatever but the question is: if you head one blanket and nothing else would you rather build a heat shield from it or wrap yourself around with it.

Obviously I'm leaving out other ways of keeping warms such as building a bed with hot rocks underneath, dig ins with heat vents, etc etc...

Well the angle is of no relitive importance of how effective it will work.

That being said is that the angle determines where the heat will be reflected.

Say you are camping a flat 90 degree reflector place beyond the fire will direct it towards the shelter. Depending upon size angling it slightly towards the fire will direct it somewhat downward keeping it from passing over the shelter.

As to the shelter itelf most are slanted at about 45 degrees. This is to direct the heat it reflects down toward where your body will be while sleeping.

Basically play with the angles to im the heat whhere you want it to go.

Actually a combination would work best.

A wood log or stone or whatever shield on the opposite side of the fire perpendicular to the ground to reflect the radiant heat back towards the fire. And then the space blanket behind you at a 45 degree angle to reflect the heat down towards your body, presuming you're intending on sleeping. If you need the blanket to wrap yourself, as you suggested, then another perpendicular structure will suffice.

In a true survival situation I would block the wind. Even though it seemed to act as a fan to carry the heat towards you, it still robs your body of heat (wind chill), as well as burns your fuel faster.

BTW, I honestly haven't tried any of this personally, other than ad hoc wind breaks on campouts. But I think it will make an excellent weekend activity for our troop at the next campout!

Oh, we had three scouts build a survival shelter by leaning deadwood branches and leaves against a tree trunk at out December outing. They then spent the night in it with their sleeping bags and ground tarps/reflective pads under them. Temps were in upper 20's. The oldest was 14. The rest slept in the heated cabin!

Here is how I use a reflector.
First, I put it behind me. So the fire is in front of me and the reflector behind me. I put the reflector in a “V” shape and I try to sit in the center of the V. Heat strikes the reflector and is bounced onto my back.

If the wind is blowing, I put the whole arrangement so my back is to the wind. Then the reflector also acts as a windshield. Problem here is that it can also act as a “chimney” causing the smoke to move towards you. Depends on the situation.

Build a very small fire. Probably the smallest fire you can make and still keep it going easily. Keep the whole arrangement close together. Distance from fire to shield is just enough so that I can get in between them. Be wary of sparks. Space blankets melt/burn depending on construction.

I can support the space blanket with my walking stick. Only one post needed. The rest of the support is done with rope. But 3 poles are better and provides more room. Although the one pole system seems to take strong winds better but does not provide as much space for me.

I was gonna put a picture here, but I guess it has to be on the web someplace. Don't have time to figure out how to put the picture someplace so will skip that for now. Perhaps later.