Harris Tweed from the Outer Hebrides in the Western Isles of Scotland.

But seriously, plastic polyester fleece has it's place, if you can live with its downsides.

Fleece isn't particularly warm compared to multiple layers of good quality thin silk/merino wool mix or down or even synthetics designed purely for insulation such as primaloft.

I wouldn't want to be wearing the same fleece garmet for more than 3-4 days. The grotty feeling wearing fleece for extended periods is a real downside. Fleece needs to be regularly laundered whereas wool garmets can go on for weeks before they you begin to notice your own stink. Never use fleece trouser/pants for extended use as a sweaty itchy smelly groin area does nothing for morale. Which of course makes one really wonder how often they do the laundry on the Star Ship Enterprise. Well lets just say I've never seen Captain Picard say 'make it so' to his washing machine in the 25th Century.

Fleece is made from polyester and will catch fire and burn easily. If in a survival situation i.e. open camp fires you will need to be especially careful that the fleece garmet doesn't become a serious liability.

Choose you fleece fabric carefully as each fabric weight has been designed for very specific climatic conditions. Windproof fleece such as Polartec Windbloc or one of its variations/competitors such as Gore Windstopper can be very useful for cold high activity use.

Overall I would say that Fleece is just as much a compromise as a good woolen sweater and good woolen sweaters are now remarkably cheap considering the expected long term use you would get from a woolen garment. Good quality fleece isn't really all that cost effective and very cheap fleece will effectively do the same job as the more expensive fleece if your not really bothered about how dapper you look after a few weeks of use whereas Harris Tweed could still look the business even after many months of hard use.

Whilst out shopping today at the local DIY store, I came across a fleece Snuggie and I couldn't help but be reminded of the Carousel Death Ritual from Logan's Run.