Make sure to protect your laptop from the cold. Most computers could get in trouble if exposed to temperatures below -15°C (the display typically being the weakest part). 

Protect the computer at night in your sleeping bag, or better yet, have a dedicated sleeping bag for all your electronics.

Add a few tightly sealed hot water bottles in the evening. You can also rig a heating system using a Hottronics heating wire (check the Everest guide).

During daytime and inside the tent it will get warm enough for electronics in most parts of the world. If skiing the Poles, you'll have to protect the computer on your body, as it could freeze on the sled. Opt for wearables or PDAs.

Always check that the computer is above freezing level before starting it up. Check the manual and call the manufacturer for specifics regarding lowest temperature. Remember that manufacturers often put the specs far above actual tolerance to be on the safe side.

Protect the unit well from dust and dirt. Dust is devastating to a computer. It penetrates keyboards, PCMCIA-slots and ventilation holes. Seal as much as possible with duct tape, put a plastic cover over  the keyboard and be creative when plugging the fan. If doing most of your computer work inside a tent however, the need for cover up is less important.

Protect from wear and tear. A soft computer pack should be sufficient for most situations but a foamed Pelican case adds protection during transportation.

If computer work is important to you and your sponsors, never leave without a back-up unit. A large Himalayan expedition will need three laptops to be on the safe side. And don't forget to configure them for the Sat equipment before you leave home .

IPAQ PDA's have been left out overnight in down to -40°C - and survived! They've swum in Arctic waters and survived! They have also arrived at the kitchen table fresh from the manufacturer and refused to start up. The units are relatively new on the market and still somewhat volatile, but when they work (as they do in most cases), they are brllliant! 

It's not recommended though to drop them in the snow, even if they are from a great batch, as the iPAQ could lose all information when exposed to extreme cold. Keep the iPAQ in your inner pocket while climbing/skiing and in the sleeping bag during the night.

There are rugged cases on the market but they are heavy and bulky. The best protection is a cushion made of foam or neoprene and a zip-lock plastic bag. Keep the iPAQ in the zip-lock at all times except when in use. In all cases, handle this piece of electronics with great care. If you do it will serve you well and you'll absolutely love it.

Warning!

If the iPAQ's battery dies you will lose all programs and settings. Some of those might not be possible to restore from the expedition. Use Pocket Backup from www.spritesoftware.com to back-up all data to your Flash card or SD card. Restoring the data is easy and doesn't take more than a minute or two. 

Pocket Backup is included in the newer versions of iPAQ.

Do not power up the iPAQ (or any liquid crystal based display) without first thawing it to above freezing temperature.

Manufacturers often brag about the ruggedness of their products, but forget to apply the same procedure to the cables and peripherals. The Iridium phone can take a tremendous amount of beating - but the data kit breaks easily. The data kit for the Thuraya phones have broken in the first day of usage for several expeditions.

Be extremely vigilant in protecting the cables and data kits. Tape over weak parts, connect them strongly together and store in protected spaces.

Shelter all connected surfaces from dirt and wear.