I just noticed in the instructions that you are to place the thermacell in a horizontal position when it's in use. Why is this? If it's vertical does it over heat the top and cause it to melt???

Not going to overheat.  Just to let the heat come up through the mat better I would imagine.  The heat is so low it may escape from the top without burning the mat if vertical.  It works fine for me just hanging vertical on the strap in a treestand so I wouldn't worry about it much.

The units have a very small heating element, which is positioned near the center of the chemical matt when in the horizon position.

That way all the heat is directly under the mat so it will work best.

Might want to contact them if you need more answers.

Think it has to do with the venting in the back of unit. In horizontal position more air flows from the back past the heat and the pad releasing more chemical.  I have noticed big difference here in Florida better coverage when unit is in the horizontal position and just below where I sit in my stands on the windward side.

Heat rises!  Directly under the matt is best for the heater system to work properly.  Horizontal accomplishes this.

When on stand, I arrange it so it's horizontal(it works best).
On the way to my stand I hang it in whatever position on my pack.
You need one here in Fl. especially for warm weather hog hunting!

Hunted with one last year for the first time and loved it. I simply put it between my feet horizontal under my treestand seat.


nocams

Thanks. I think you're right about it putting the heat directly under the mat for better coverage. One more question; do you turn yours on before you get to your stand or while stalking?

I've stalked with mine hanging vertically strapped to my pack.  Seems to work fine that way, too.  But, if I sit, I lay my pack flat so the Thermacell is horizontal.  

Takes about 10 or 15 minutes for mine to really get to cooking, so if I know I'm going to have a flying vermin problem, I'll turn it on and get it heated up before I get to the stand.

I take a small bungie cord with me an strap it to the back rail of my stand .It must lay flat for best results.Iam always afriad I will kick it off with my big feet that is the reason for the bungie cord.that is one great tool for swamp hunting.