Having just ended a week away in a foreign country, operational security (Opsec), health and protection abroad is a topical subject.!

Travelling abroad mixes us together with people that we are not familiar with, from various cultures and backgrounds, both locals and other foreigners. With this brings it's own potential dangers, diseases or germs that you are not used to.
As a foreigner or traveller you are always vulnerable and a potential target for the criminal element.

Preparation

Good preparation can make your trip go a lot smoother, less stressful and more enjoyable. I am lucky in that my wife takes care of the plans for our personal trips. Technology provides us with many tools that can be used to aid preparation.

Tripadvisor is a great crowd rating tool that can be used to check out accommodation and destination. Security, sanitation and food ratings should be a priority to check, on our trip this time my wife had said that her choice of hotel was based upon the exceptional food quality rating and that the hotel manager had responded to all of the comments made.
Google Earth is a good tool to visualise where you are going, here you can see buildings, land topology, water courses, etc.
Google street view allows to to visit virtually and become familiar with your intended destination.
Use the Internet to look at security of the area and legalities for your Everyday Carry (EDC) items.
A map or print out showing locations of the medical facilities in the area is a bonus.!

If you have a mapping App on your mobile phone make sure you download the country map prior to departure, the Apple App security may require additional personal data when using foreign WiFi, if this happens to be a credit card that you haven't brought with you then you can't download!
Journey

Travelling abroad especially by aeroplane restricts your EDC, the security restrictions imposed at the airport further limit what you can actually take in your carry on baggage, this puts you on a back foot from the outset, however with good planning you can still take some useful items with you.

Check in baggage

Use your check in baggage to take items not allowed in your carry on baggage, however remember if the main purpose of your trip is an holiday the pack accordingly with this in mind and don't let you prep's encroach too much into your holiday gear, after all the whole point of the trip is to have a holiday and relax. Opsec should be covert.
This is a list of items that we took with us on this trip; 3" folding pocket knife, compact Southord lock pick set on a compass key fob, SOG multi tool, small high power LED torch, back up batteries, two N95 medical masks, Lifestraw Water filter, 2 light sticks, first aid kit, solar / battery bank charger with a multitude of connectors.

Carry on / EDC

I use a backpack as my bag, this also serves as an EDC or BOB when we arrive at our destination, in this bag I have paracord discretely woven to avoid attention, my keys which are attached into a pocket of my bag include usb memory stick fob that contains data, photographs that could be useful in an emergency. I take a change of clothes just in case my main baggage is lost, my mobile phone and iPad security locked, a portion of the cash that we are taking (my wife will carry the remaining), my wallet is stripped to just 1 credit and 1 debit card, all other ID is removed.

Once through security additional items can be purchased to take onto the plane, water should be a priority and food if you need it.

Use the time at the gate lounge to do a basic identification of potential threats (IPT), it's your only time to watch people covertly all together in one place other than on the plane itself, I look for associations between people and groups, the people travelling alone and those in groups who could potentially be rowdy and a threat.

On board any public vehicle where available, we always wear seat belts and direct the air blowers into our personal space preferably the face, the air is usually filtered to some level and is a positive air pressure, we feel that this goes some way to protect against peoples expulsions, coughs and sneezes.

Disembarking of the plane is usually tight and you can be in close proximity to others so be aware of your personal belongings. Once through security and baggage collection I like to find a quiet spot in the airport to transfer my EDC items from my baggage to my bag and pockets. It's also a good time to pick up more water and food if required.

Try to obtain a map as soon as you can in the trip, even if it's a free advertising version so you at least have something physical.
On this trip our transfer to the hotel was by coach, the large baggage is stowed under the coach and typically the loading doors both side of the coach are left open awaiting other passengers. Where possible I like to sit up at the front as it's easy to observe people as they board, use the drivers mirrors to view the sides of the coach to ensure your baggage isn't tampered with or removed. It can take quite a while to fill the coach as multiple transfers are usually waited for, during this time my wife likes to wait off the coach and also checks the bags from there.

At the front of the coach also allows you to observe the driver, his driving style, observations and liveliness - most coach accidents are caused by drivers not concentrating or falling asleep at the wheel, here you are in the best position to take action if at all possible - It also means you get to see where you are going and take in the scenery!

Arriving and Settling in

Once checked into your accommodation do the basic checks, fire escapes, smoke alarms and window escapes along with overall room security, door locks etc. If your preparation was good there should be no problems.

If there is a room safe that is either free or low cost try to use it, otherwise hide away you money, passport and valuables.

Agree upon a meeting point should you get split up or lost, also since the tsunamis I always check our elevation to sea level and agree an high point if at or close to sea level.

Our preference is to hang the "don't make up my room" or "do not disturb" sign on the door for the duration of the visit, we would prefer to make up our own room rather than risk a complete stranger going through our stuff. If you do need the room cleaning or towels changing try to ask the maids whilst you are around.

We always use bottled water for drinking and brushing, rinsing your mouth and toothbrush. If you are concerned about the water or you just want to avoid consuming it consider the common things that water is used for and avoid them, e.g.

Salad washing
Hotel coffee/ tea vending - something I never really thought about in the past but these are plumbed into the mains water and certainly the ones on our trip this time never heated the water to boiling.
Soda pumps - these also looked like they are directly connected to mains water.
Ice - from what I see most of these are purchased in bags by the bars so its likely that they are under the same restrictions as filtered water sale, but look out for bars making their own ice, the input water is likely to be mains supply.
For further reading check out NHS advice on Water Abroad

Out and about

I don't tend to leave my room key with reception especially where they are clearly on show for all to see or can be easily reached out of the key deposit box, it is so simple for a thief to ask for your room key and in the early days at least the receptionist won't know you from Adam!

Sunglasses as well as being protection for the eyes also go some ways to mask your expression from others this comes in handy during confrontation or even simple bartering for that new T Shirt at the market!

They also allow you to discreetly check your peripheral vision without turning your head. using peripheral vision is something that should be practised often, it can provide you with that extra split second reaction time that could potentially could save your life, e.g stepping off a pavement or pulling out in traffic.

Be aware of your surroundings - I had a potential incident whilst walking out at night with my wife, upon hearing someone approaching faster than our walking pace to my left and walking hand in hand with my wife on my left, a discreet peripheral check confirmed that a young man was approaching quick and towards us, I slowed my step and passed my wife in front of me to my right, allowing the man to pass to my left where I could have controlled the situation, all this in a split second, my wife was none the wiser that I had made that move, awareness of your surroundings is crucial at all time.

This same principle is something that I think should be done when walking with young children, I personally have always kept them away from the kerbside of the pavement and away from the passing vehicles to allow me split second reaction time to take action should it be required.

Walking on the road always face the oncoming traffic to allow you to see them and them to see you, if they haven't seen you you have time to react - remember that they may drive on the opposite side to what you are used to - also remember this when crossing a road.

In crowded areas I tend to have my thumb touching my phone or wallet in my front pockets, however be conscious not to tap the location of your wallet as you pass the "Beware of pickpockets" signs, it's a dead give away as to the location of your valuables.

Check your IPT at every opportunity when entering new areas, restaurants, buildings, etc, know your exit points or safe areas should you need them. Even at the beach, let us we not forget the recent shootings in Tunisia.

Medical and insurance

Travel Insurance should be acquired for trips abroad, you just never know when you are going to need something. Check to see if you get this as a part of your banking fees. In the UK we can obtain a European Health Insurance Card (EHIC),

it's free but not standard issue and has to be applied for, it's surprising how many people don't know about this. My wife adheres ours into our passports so they always travel with us. Up until now we have had no cause to use it, however sometimes it doesn't matter how much you prepare mistakes can be made, on this trip my wife forgot to pack one of her prescription medications, luckily it wasn't life threatening but could of meant a very uncomfortable week for her without them, I have a similar medication with less strength so we immediately put a plan in action to ration these if we couldn't acquire any more. We found the nearest medical centre and explained the situation, they asked for our EHIC and we were able to obtain a prescription free and of charge paying only for the drugs at the chemist.

I am sure that I will add to this post in time - if you have any comments or additions please let me know and I'll be sure to add them.

Enjoy your holidays or trips, prepare well, be aware and trust your instinct.