Best Men's Thermal Union Suits

Dual-Layer Warmth

Two layers of fabric, including merino wool, help make this union suit a favorite choice for our fitness expert, though they're too warm for vigorous exercise.

Dual-layer construction for excellent insulation. Outer cotton-wool-nylon layer is 25% merino wool for natural warmth. Inner layer is 100% cotton for familiar comfort. Full button front placket and button-closed seat flap. Three color options.

Premium Thermal Union Suit

Fabric is not especially moisture wicking.

Best Bang for the Buck

Fruit of the Loom

Comfortable Favorite

A comfortable, moisture-wicking union suit from a well-known brand that also works as loungewear and pajamas.

Made of 52-48 cotton-polyester blend ribbed fabric with natural stretch. Front placket has standard button closure extends to gusset for convenience. Button-closed rear opening. Offers moisture-wicking capabilities. Tight cuffs.

Not form fitting. Can seem loose near the gusset.

A lightweight, stretchable union suit made of pure cotton for a classic look and feel.

Made of 100% cotton. Lightweight 5.5-ounce rib cotton fabric combines warmth with ease of wear. Ribbed cuffs on wrists and ankles to retain heat. Full button placket and vertical rear flap. Tagless design to avoid irritants.

Force Classic Thermal Layer Union Suit

Shrinks after first wash. Must wash in cold water.

Carhartt

Sturdy Waffle Weave

A comfortable union suit with a classic waffle weave from a favorite workwear brand.

Fabric is 60-40 cotton-polyester blend. Classic waffle weave traps warm air close to the skin. Front placket features easy open snap buttons. Rear opening tucks for closed in waist. Flatlock seams and tagless labels. Four color options, including camouflage.

Cotton Rib Onesie Winter Underwear

Rear opening can be drafty for some.

Stanfield's

Reinforced Cuffs

This union suit is made of pure cotton and boasts Spandex-reinforced cuffs at the wrists and ankles.

Made of 100% combed cotton. Snug fit for skin-hugging warmth. Ribbed wrist and ankle cuffs are reinforced with Spandex to seal and stretch. Full button front placket and rear opening. Tagless for chafing reduction.