Survival kit part 3 (shelter)

Here in the UK one of the biggest dangers is exposure, or hypothermia to give it it's proper name.
The bodies natural core temperature is around 37c, a drop of only a few degrees can put a persons life at risk.
Just a really cold day can put you at risk of exposure if your not adequately dressed for the conditions, add in rain and wind at there's a very real risk of problems, as the wet tends to affect any insulation your clothes give and the wind adds wind chill.

Now there are a million ways to build a simple shelter,but remember we're doing this the easy way, we want to use as little effort as possible.
Look for a ready made shelter, caves are the obvious one that comes to mind.  Don't use beach caves though unless your totally certain the tide doesn't get up to them, being trapped in a cave by the rising tide isn't going to make for a good day out.  And remember the tide varies with the time of year, so there are some tides a lot higher than others. You have been warned!
The next shelter is to look for just getting out of the wind, that can make a huge difference in temperature
Sometimes just dropping a few foot and tucking yourself in behind a small bank stone wall, fallen tree or bush will work, it goes without saying you need to be on the lee side of the bush or whatever.  Failing anything handy to get behind can you built a small wall of stones?  I've done this myself, in the army their called a sangar (sangar is Persian for temporary wall or breastwork ) A small wall doesn't take too long to build if theres plenty of handy stones, the thing to watch is to make sure it wont collapse onto you, it also doesn't need to be too high.
Another option if theres branches is a simple lean to, just rest lots of branches against another tree or big stone, whatever and cover with anything you can find, even leaves will help.
Now we come to the survival kit option, why not just carry some sort of shelter with you. Again some of this stuff can be found cheaply if you search around, I found a reflective (space blanket) bivibag for under £2 on ebay, it's small and light, ok it won't actually fit in your survival tin, but it'll go on top, or in another pocket. Theres also plastic small light bivibags, or the bigger heavy duty model, too big for everyday carry though unless your taking a backpack
Another option is a small lightweight poncho, some outdoor concerts give these away and I've seen them in the pound/dime stores as well.  Ok you won't win a prize at Paris fashion week but who cares if you stay dry.