Hillwalking is a wonderful recreational activity - it's a healthy form of exercise, it doesn't cost much to get started and you can do it in most counties in Ireland. But there are risks attached, newcomers to the hills need to be aware of these risks and take sensible precautions.
The risks on the hills are caused mainly by three factors: weather, terrain and remoteness.
Before starting out, decide where you are going and how long the walk should take. The distance you walk, the amount of height gained, your fitness and the fitness of those you walk with, will all influence the time your walk takes. Other factors such as the weather and the type of ground you're walking on will also affect your timing. It's easy to under-estimate the time required, so start by choosing shorter routes and noting the time taken. There are many hillwalking guidebooks available, which include route descriptions, plus distance and estimated time. Get a weather forecast for the area and ensure you have time to get off the hill before dark.
Weather changes in the mountains - the higher you go in the hills, the lower the temperature (drops 1°C for each 100 metres of ascent); the wind is stronger up there (2 to 3 times the speed in the valleys); there is more rainfall (3 times that in the valleys) and there is more risk of mist and cloud (mist on the tops 3 days out of 5). Weather conditions can change in minutes in the Irish hills and you need to be equipped to cope with this.
Walking boots with good ankle support are essential when walking off-road. Always wear clothing suitable for the outdoors and carry spare warm clothes at all times. Jeans and cotton should be avoided (if they get wet they will not dry, causing loss of body heat and energy and possibly contributing to the onset of hypothermia). A waterproof jacket and over-trousers, warm hat and gloves are essential, irrespective of the weather on starting out.
Carry a rucksack for spare clothing, food and a hot drink for the walk plus some spare high-energy snacks such as chocolate, glucose sweets or energy bars. A torch, whistle, small first aid kit and plastic survival bag are also useful.
Know where you are in the hills at all times. This involves having a walking map - usually 1:50,000 scale (waterproof or in a case), compass and, most important, the ability to use these effectively in poor visibility. Most mountain rescue call-outs, whether for missing or injured persons, arise from an initial error in navigation. Be careful about foot placement, as there is always the risk of concealed holes, rocks, slippery ground and soft bog. Be particularly careful when descending steep ground and when crossing streams and rivers. Streams in flood are deceptively dangerous. Most accidents happen on the way down, when people are tired, rushing or no longer paying attention.
It's better not to walk alone in the hills, particularly if there aren't other people in the area, and if alone do not take any chances. The remoteness of the hills in bad weather can be very unnerving, even for experienced walkers, and can lead to serious mistakes being made.
Try to leave word with a responsible person about where you will be walking and at what time you expect to return. Mobile phones can be of help in emergency situations or for calling to say you will be back later than expected, but never rely on being able to use a mobile phone in the hills as coverage is often poor. Never do anything which you would not do if you did not have the phone with you.
In an accident or emergency situation, stay calm and take time to think things through. To get help phone 112 or 999 and ask for Mountain Rescue. The recognised mountain distress signal is six blasts on a whistle, or six flashes of a light, in succession followed by a one minute pause and repeated until you get a response (three blasts or flashes is the appropriate response). Mountain Rescue is a voluntary service and should only be contacted in a genuine emergency.
Think about doing a training course in hillwalking, for example the popular Mountain Skills scheme (usually run over two weekends). The skills of navigation are simple, it just takes a bit of practice and it will greatly improve your enjoyment and safety in the hills. Alternatively, join a hillwalking club, there are social benefits and you will also have the company of experienced walkers. Many clubs also provide training for their members.

More information is available on the Mountaineering Ireland website here