creating a light that works on a blood pressure sensor/heat sensor

Hey

I'm new here and have recently been thinking that I want to create a light that would work (i.e. turn on) when specific readings from the body are met. So far I have when a low and stable blood pressure reading is met (indicating happiness) or when a specific temperature reading is met (also can indicate happiness) I think I'm more inclined to want to build it with the blood pressure reading as the heat one could just turn on if you are hot.

However I have HONESTLY no expeirience in building electronics but am really keen to learn! Could anyone point me in the right direction to where I should be looking please and what some of the steps I am going to need to take are please? 

In my mind it would work when a blood pressure reading is taken and the monitor shows a reading within the healthy and happy range. However I literally have no clue how to tell a lamp to turn on when this is achieved 

please please help me out! 

thank you so much in advance
Holly :^)