Choosing a bivvy and a sleep system for cold nights

The shelter and the sleep system decide how you feel at six in the morning, and how you feel at six in the morning decides whether you fish the last two hours of the session properly. They should be chosen together, against the season you actually fish in.

The bivvy

• Size it for the season: a compact bivvy is warmer and quicker to pitch in winter; a larger one gives room for kit in summer.
• Look for a groundsheet to keep the damp out, and for a clear window so you can see your rods from inside.
• Ventilation matters more than it sounds — condensation inside a sealed bivvy will leave you wet even on a dry night.
• Pitch it facing away from the prevailing wind and peg it properly before dark.

The sleep system

A bed chair and a sleeping bag is the standard combination, and the bag is the part to get right. A bag rated for the temperatures you expect, used with a mat or a bed chair that insulates you from the ground, will keep you warm; a bag that is too thin cannot be fixed by piling coats on top.

• Match the bag's rating to the coldest night you expect to fish, not the average.
• Insulation from below matters as much as the bag itself — the ground draws heat out of you all night.
• A pillow makes the difference between resting and not sleeping, and it takes no room.
• Base layers, dry socks and a hat do more for warmth at 3am than a heavier bag.

Light and heat

A lantern gives you light for the swim without the harshness of a headlamp, and a headlamp gives you hands for tying a rig or unhooking a fish. A stove and kettle will not just keep you drinking — a hot drink is the quickest way to warm up when you are cold and tired.

Never use a gas stove, lamp or heater in a closed bivvy. Ventilate, or take the heater outside the bivvy.