Boucle can be made out of a lot of different things, but I would say if you're not used to working with it try something acrylic, like Bernat soft boucle yarn. As an acrylic, it can be machine washed and is very durable.
cold sweat - the physical condition of concurrent perspiration and chill; associated with fear. fear, fearfulness, fright - an emotion experienced in anticipation of some specific pain or danger (usually accompanied by a desire to flee or fight)
Sweating is a bodily function that helps regulate your body temperature. Also called perspiration, sweating is the release of a salt-based fluid from your sweat glands. Changes in your body temperature, the outside temperature, or your emotional state can cause sweating. Sweating in normal amounts is an essential bodily process. Not sweating enough and sweating too much can both cause problems. The absence of sweat can be dangerous because your risk of overheating increases. Excessive sweating may be more psychologically damaging than physically damaging.