Fleece: Fleece pajamas should definitely not be washed in hot or warm water. Instead, rinse them with cold water, very lightly. Spot cleaning instead of machine washing is preferable. Then, lay them out to air dry and once they are dry using a bristled comb to brush the lint out and make the fleece clean and fluffy.
Wool: Wool pajamas can be washed, but use lukewarm water and a mild detergent, and they should be good to go!