A convective warming blanket has a head portion and a plurality of peripheral sections extending orthogonally from each side of a central section that extends uninterrupted from a proximal end below the head portion to a distal foot end of the blanket. Each peripheral section is separable from its adjacent peripheral section by a frangible or tearable common seal. At least one through passage connects each peripheral section to the central section, so that the peripheral sections are inflated when heated air is input to the blanket. The multiple peripheral sections each are movable relative to the central section, so that different body parts of the patient may be selectively accessed. The head portion of the blanket is formed by two tubular sections that extend from the proximal portion of the blanket to encircle the head of the patient, when the blanket is placed over the patient.