A tourniquet release device 3 comprises a body 5 having first 7 and second 15 parts for retaining first 11 and second 17 portions of a tourniquet strap 13. The body 5 or a leg 19 thereof - is further movable between two conditions a first in which the strap 13 is prevented from disengaging from the body 5, and a second achieved after a period of time, in which the strap 13 is able to disengage from the body 5. A suction cup 25 provided with a means 33 for allowing the ingress of air into the cup 25 may act as the means for actuating the transition between the conditions. A time indicator in the form of a blister containing a coloured liquid, whereby upon rupture of the blister the liquid penetrates a porous portion of the device, is also taught. The extent of penetration by the coloured liquid provides an indication as to the time elapsed since the blister was ruptured. An indicator (280, Fig 9) which becomes visible to a user after a plug (209, Fig 9) of a tourniquet strap has been inserted into the body a predetermined number of times is also taught.
