are you allowed to take blankets on the plaine?
yes, but most airlines already have blankets. Southwest does not have them. Most airlines who have blankets though are getting rid of pillows or already have with the exception of international flights.
Am I probably allergic to cashmere if I'm allergic to....?
Allergy only develops only upon contact with an allergen - so, if you haven't worn cashmere, you shouldn't be allergic.
I get really hot when I sleep. What is the best material for my sheets to keep me cool?
Try silk or a high thread count 100% cotton and sleep in the nude! Its better for your junk anyway.