When the dress code is business casual but the forecast warns of oppressive heat, the right choice is a blazer made of summer-weight fabric. The material should be lightweight and breathable, with the top candidates being linen, cotton, hemp and lightweight wool.

Ideally, the blazer is also unlined — a style that cuts unnecessary weight and softens the silhouette for a more casual aesthetic. Summer-weight blazers work well with everything from chinos and a tie to jeans and a t-shirt, and with proper preparation for the upcoming heat, you can stay cool without sacrificing style.

Outerknown Ambassador Blazer

This blazer is cut from a linen-wool blend that is strengthened with a touch of nylon. The design features a notch lapel, a two-button closure, seams finished with an organic cotton binding and Bemberg-polyester-lined sleeves.

Beams Plus 3 Butto Seersucker Blazer

Made in Japan, this blazer is cut from a cotton-poly lightweight seersucker fabric. It features a notched lapel, three pockets and a three-button closure.

Club Monaco Grant Linen Suit Jacket

Made from breathable Irish linen, this slim-fit blazer features notch lapels, a chest welt pocket, two front flap pockets, a double vent and four internal pockets.

Lardini Unstructured Linen Blazer

Made in Italy, this linen blazer includes shirt-style buttoned cuffs, making it a great option for more casual occasions. The design features notch lapels, two front patch-pockets and buffalo horn buttons.

Man 1924 Kennedy Linen Blazer

This blazer has functioning buttoned cuffs, notch lapels, three front flap-pockets and a single vent. Cut from brown linen, it features hand-stitched finishing.

Officine Generale Unstructured Herringbone Linen-Blend Suit Jacket

Made from a breathable blend of linen and rayon, this blazer features notch lapels and cuff, patch pockets and a slim profile. The subtle herringbone pattern seperates it from similar blazers.

Eidos Unstructured Linen Blazer

Made in Italy, this linen blazer features notch lapels, a chest welt pocket and two front patch pockets. The lightly textured fabric is a departure from similar blazers.

Rubinacci Unstructured Herringbone Linen Blazer

This Italian-made linen blazer features functioning buttoned cuffs, two front patch pockets, a double vent and a three-button closure. The fabric features a very subtle herringbone pattern.

Lardini Unstructured Cotton Blazer

The cotton used here is woven to be naturally breathable, giving the blazer a distinct texture. The design features notch lapels, a felted undercollar, a double vent and buffalo horn buttons.

Loro Piana Virgin Wool and Hemp Blend Hopsack Blazer

This jacket is a unique blen of 55 percent virgin wool and 45 percent hemp. The textured fabric is comfortable and breathable, and the blazer’s desing includes notch lapels, a double vent a three-button closure and buffalo horn buttons.