Blankets were traditionally made of wool, while sheets were made of cotton which is less irritating to the skin. These days, artificial fibers are frequently used for both. Duvets vs Comforters: http://www.ajmoss.com/blog/2006/06/01/co... How to fit a Duvet Cover: http://www.bbc.co.uk/dna/h2g2/brunel/A68...
An easy swim burns around 500 calories an hour, while a vigorous effort can reach up to 700 calories an hour. Swimming exercise provided workout for lower body, upper body, core, and back will all be worked and strengthen during a good swimming workout, you can go for 4 to 6 days swimming workout.
Swimming does burn calories at a rate of about 3 calories a mile per pound of bodyweight. If you weigh 150 lbs. and it takes you 30 minutes to swim one mile (1,760 yards or 1,609 meters), then you will be using about 900 calories in one hour.