Wristwatch consists of two modules - a first module (12) with a normal time-keeping function, and an additional module (3) designed to monitor the health of the wearer or apply medication. Wristwatch consists of two modules - a first module (12) with a normal time-keeping function, and an additional module (3) designed to monitor the health of the wearer or apply medication. The two modules can occupy two different positions : one in which the second module is covered by the first to give the appearance of a normal watch, and a second in which the two modules are separate and the second module is exposed for access. The two modules can be interlinked, so that medication is applied through an applicator (G) at times transmitted by the watch.