Thermal Pajama Sets

thermal
An upward current of warm air, used by gliders, balloons, and birds to gain height
A thermal garment, esp. underwear
relating to or associated with heat; "thermal movements of molecules"; "thermal capacity"; "thermic energy"; "the caloric effect of sunlight"
of or relating to a hot spring; "thermal water"
rising current of warm air

pajama
Pajamas, also spelled pyjamas (see also spelling differences) can refer to several related types of clothing. The original paijama are loose, lightweight trousers fitted with drawstring waistbands and worn in South and West Asia by both sexes.
a pair of loose trousers tied by a drawstring around the waist; worn by men and women in some Asian countries
(usually plural) loose-fitting nightclothes worn for sleeping or lounging; have a jacket top and trousers

sets
A collection of implements, containers, or other objects customarily used together for a specific purpose
(set) put: put into a certain place or abstract location; "Put your things here"; "Set the tray down"; "Set the dogs on the scent of the missing children"; "Place emphasis on a certain point"
(set) fit(p): (usually followed by `to' or `for') on the point of or strongly disposed; "in no fit state to continue"; "fit to drop"; "laughing fit to burst"; "she was fit to scream"; "primed for a fight"; "we are set to go at any time"
A group or collection of things that belong together, resemble one another, or are usually found together
A group of people with common interests or occupations or of similar social status
(set) a group of things of the same kind that belong together and are so used; "a set of books"; "a set of golf clubs"; "a set of teeth"