Monday 28 January 2013

Mountain Bike First Aid

Finding a decent first aid kit for mountain biking is actually pretty tricky. I want a kit that can cover all eventualities.

Coming off at speed on forest single-track means potential cuts, bruises and breaks. Coming off when there's fresh cut logs and offcuts in your landing zone can mean potential punctures and major trauma.

I've recently got quite excited about first aid after completing the RNLI's casualty care course. That covers first aid with a few things thrown in from field medicine. Taking this into account I started looking for kit I should take on the trails with me, it needs to be relatively light and capable of dealing with the worst possible situations. That being the case I'd rather have fewer items to cover all eventualities.

Similarly I don't want to cock about cutting gauze, and using tape. My kit is designed to be applied very quickly.

So, what do I currently have in my kit?

Note: I'm in no way affiliated with SP Services, I just found that they were the easiest to order from.

Gloves - I have a couple of pairs of latex-free medical grade disposable gloves wrapped up in sandwich bags. So far I've only had to fix strangers I've run into on the trails. It's always a good idea to wear gloves. Not just so you don't catch something. You might not have time to clean _your_ hands. Wearing gloves provides a barrier that protects you both.

Ambulance Dressings - these are wraps of bandage with gauze sown in. The gauze is sown in about 20% of the way around the roll. This means you can very quickly apply the bandage to the wound, wrap it a few times and then tie the working end to the slack 20% on the other side of the dressing. Incredibly quick and effective. They're very light and cheap, costing about £0.40 each, I typically carry 3-4 of varying sizes. They can be used to make slings, treat head wounds or cuts. They can also be soaked in water and used to pack open fractures and large wounds. Inexpensive, light and multi-function - so much more useful than carry rolls of bandage, gauze and scissors. With the extra advantage of being usable when your hands are shaking.

250ml Sterilised Water - useful for irrigating wounds or simply as eye wash. In some situations when help is near you might not choose to irrigate and prioritise getting the casualty to professional medical care but when mountain biking the casualty could be hours away from professional help so it's worth taking the extra few minutes to irrigate a wound.

Triangle Bandage - Very useful for making high or low slings, also foldable into a normal bandage, can be soaked and folded to pack an open fracture. Cheap and light.

Foil Blanket - If the casualty can't get themselves moving then it's time to wrap them up. Dress whatever wounds they have, layer them up with whatever clothing is spare and throw the foil blanket over them. This only works while the casualty is warm, putting foil over someone who's already cold won't make any difference. Cheap and light.

Plasters - Light and cheap, useful for small abrasions and when stuff is rubbing, can also be useful for running bike repairs in a pinch.

Face Shield - For use in CPR. Don't expect to need this but it's light and worth having. If you don't have one in your kit then persist with hands only CPR.

Emergency Care Bandage - Amazing bit of kit, generally only required for large truama wounds. Deep cuts, punctures etc. They can soak up an amazing amount of blood and have a very clever plastic part that allows you to apply direct pressure to the wound. Similarly you can apply a windlass technique to put massive direct pressure onto a wound. These are not cheap at about £5.00 each, I only carry one in my pack and will always look to use an ambulance dressing first if appropriate.

The ECB really is a great bit of kit :


Summary:
2 x Pairs Gloves
3 x Ambulance Dressings
1 x 250ml Sterile Water
1 x Triangle Bandage
1 x Foil Blanket
1 x PackPlasters
1 x Face Shield
1 x Emergency Care Bandage

I bought most of my kit from SP Services which is the only place I could order individual items for my kit. I had to add a second ECB to meet the minimum order price.

I'd love to hear any suggestions for extra kit or swap-outs.

I also carry ibuprofen, aspirin and paracetamol. I use these to treat specific types of injury or illness but don't want to discuss medication here as I'm not a doctor.

Tuesday 8 January 2013

SSH Chaining / Bunny Hopping

Sometimes you're in a situation where a server on a restricted network needs SSH access to another server outside of that network. Here I explain how an intermediary server (one accessible from both networks) can be used to allow an end-to-end SSH connection.

Host A is inside a restricted network and cannot SSH to the outside world.
Host B is in a different part of the network, is accessible by Host A and _can_ SSH to the outside world.
Host C is a server off on the internet somewhere

On Host A, we use SSH to create a tunnel via Host B to Host C. This opens a local port on Host A (2222) that will forward packets to port 22 on Host C. Note that the packets are encrypted in the tunnel between Host A and Host B but not necessarily between Host B and Host C.

Run from Host A to setup the tunnel:

ssh -f user@hostB -L 2222:hostC:22

Now, to SSH to Host C from Host A simply connect to the localhost using port 2222 and the packets will be forwarded to Host C via Host B.

ssh user@localhost -p 2222

This is particularly useful for transferring files around, it allows you to neatly bypass most network controls, here's an example using the above and SCP to tunnel data out of a network in an encrypted fashion  Note this is transferring DATA_DIRECTORY from Host A to Host C and placing it in the users home directory

scp -P 2222 -r DATA_DIRECTORY user@localhost:~/

Simples!