Device and method for controlling humidity at the surface of a supporting item of the mattress type

12a, bc312The present disclosure concerns a device for controlling humidity at the surface of a supporting item of the mattress or cushion type and in the vicinity of the body of an individual resting thereon, comprising an envelope formed by at least two parts connected with each other at their peripheral edges, such as being sealed by welding, defining an inner chamber, the two parts having a first part intended to be positioned on the side of said body of the individual, and a second part intended to be positioned on the side of said supporting item of the mattress or cushion type, the first part including a material forming a barrier impervious to air and liquid water and pervious to water vapor, the second part including a material pervious to water vapor, the second part comprising at least one air injection port and means for discharging air comprising perforated or porous areas pervious to air, such as perforations.