Cold ride questions

[tallcarabs@juno.com]

Ok, I just finished my mare, Scarlet's. last ride until late fall. (she's
prego).  It was a wonderful ride and I'm so very pleased with the
progress she's made in the last year.  This was our first ride to do
entirely in a D-ring snaffle, whereas before I had to ride in a long
shanked Tom Thumb -- she used to get so completely unnerved and excited
by all the horses that she would leave her brain at home and only
something strong would get through the fog to get her to be in somewhat
control.   This ride was great.  She was still excited, did a jiggy trot
for the first few miles, but never reallly pulled on the reins or tried
to run off.
 So, my questions.  It was really cold the night before - got down to 28'
F.  I fully admit to having thin blood and can handle the 90's so much
better than anything below 60'.  I got a sleeping bag that was rated for
0'F and expected to be comfortable that night.  Well, I was wrong.  Froze
my toes off and I don't think I got any sleep at all.  I think because I
was on an air mattress, that it was conducting very cold air under me and
is there anything that can be done about that????   I get sore sleeping
on the ground or a thin pallet, and really was comfortable on the
mattress, except for the cold.  Any suggestions?
   The morning of the ride everything was covered in ice.  Scarlet is a
weeny about the cold as much as I am.  When I took her blanket off to
saddle her, she was almost violently shivering.  I kept the blanket over
the saddle until we started, but I was wondering about the rump rugs --
do you ride in them when it is cold like that?  or just keep it on until
you start the ride?  When is the time to use a rump rug and when would it
be better to take it off?
     Also, on the LD -- why is the last vet check just a trot out instead
of a full check like the other two?  Even though 25 miles isn't
considered real endurance, I would still think that a full check at the
end of the ride would be a good idea.  There are still newbie riders who
may be overriding their horses, newbie horses who may be letting their
riders over do it, or even the few people who think LD is a race.
  I know I had some more, but my brain is still in a New Year's fog. :o)

Thanks
Rae
Tall C Arabians -- TX