A new aid for the elderly is being pioneered called 'Tom' and it is a digital thermometer which clearly states which temperatures are acceptable in the home (21 degree being the best room temperature). If rooms are too cold it says 'cool' or 'cold (e.g. 17.5 degrees 'cool' 15 degrees 'cold'). It recommends you either take a look for infirm relatives or friends or ring them up and say 'What does Tom say now?' so that is they say 'cool' or 'cold' you will know what is happening. They are looking for 100 families to trial the device for free and here is the website link www.howstom.co.uk/howstom/hows-tom-home . It may be useful!