I was always puzzled how a metally flimsy square of tinfoil like substance was going to keep me warm in the middle of winter in Alaska with no sunshine.
It is shiny so maybe someone will see it, it could possibly melt water.. maybe..
If it held up it might give you a bank from the wind. But you’d be better off digging a sleeping pod in the snow and either using it as a flap or if it is wet snow from getting wet. Or maybe you could use the reflection to start a fire if you didn’t have matches or they were wet, assuming the sun was strong enough that day. You could flap it at a bear so you appear bigger.
But how to make it better…. hmmm… well I always just carry a full set of winter gear and a blanket in my car and hope I never need to use it.
My best idea is an in case of emergency button: instant gps signal sent straight to the closest help facilities. I always find that my cellphone is near death or out of signal range when I need help. Once the device itself gets cold it stops working.
Oh wait I remember Bubblyboy. That might work it inflated like a cushy pod of warmth and protection from the elements.