I like to have basic emergency procedures, and as I'm about to travel I sent my 'in case of emergency' document to my parents and housemates. Some have replied saying that I was very organised, but I don't think it takes much effort. I keep an electronic document that gets updated when there is a relevant change in circumstances (e.g. change of home or employment) and keep a printed copy in the front of my diary and my luggage when travelling. It is, in fact, not much more than a copy of the personal details form that gets pre-printed in many diaries, but keeping it electronically means I don't have to copy it out into a new diary every year.

Adjust as appropriate:

* my phone number (in case I've got separated from my diary or luggage)

* home phone number (to contact housemates)

* parents/spouse/next-of-kin phone numbers

* employer phone number

* phone number of home parish + religion/denomination and any relevant details (e.g. 'last rites')

* allergies

* blood group

* spectacle prescription

* Medicare number

* private health insurance membership

* organ donor register number, or organ donation instructions

* date document was updated

For me, this all fits on one A5 sheet of paper.