from a series of flexible panels hingedly connected together thus fig4 a to 4 e show that the air guide 140 comprises a flexible face ring 141 which is connected at opposite edges 141 a 141 b to the respective filter supports 100 a 100 b in addition there are four flexible and planar panels 142 143 144 and 145 which form the rest of the air guide each of those panels is hingedly connected to the face ring 141 during the wearer 39 s respiratory cycle when the wearer inhales air passes from the external atmosphere through the filters within the filter supports 100 a 100 b to the inside of the air guide 140 and then into the wearer 39 s lungs then when the wearer exhales hot moist air exhaled by the wearer passes into the air guide 140 then through the exhale valve 220 to the external atmosphere the structure of this embodiment gives sufficient protection for use as an emergency hood panels 142 and 143 are hingedly connected together along a hinge line 146 and panels 144 and 145 are connected by a hinging panel 147 to which they are connected by respective hinges 148 149 fig4 a to 4 e also show the hinging lines 142 b 143 a 144 a and 145 b to which the panels 142 143 144 and 145 are attached to the respective filter supports 100 a 100 b thus as can be seen.