Its winter and temperatures are dropping, So you have decided to do a night on the bank, except for the change in style of fishing, keeping warm is essential as if you are cold you will not fish efficiently, you will not enjoy it and you could get hypothermia (not good).
Here are my tips to keep warm during the night. (not in any order).
Heater: Gas heaters are cheap, and I find I am using it to warm up the bivvy in small blasts as that will keep on top of the cold. I used it at the beginning of the night but always turn it off when I go to sleep. if I wake up either naturally or to an alarm, I again will have a small blast just to take the edge off.
Sleeping Bag: I would say the most essential of all. Buy the best you can, they are seasoned so look for a four or five season. When retiring remove enough clothing to make you comfortable, remember sleeping bags are designed to keep heat in and your body temperature will be retained by the bag. I always place the removed clothing in the bag, so it is still warm in the morning. If you are cold putting layers on will warm you if you have slept in all your clothes you will stay cold.
Clothes: Buy and wear thermals under your normal clothes as they are designed to trap body heat, wear thin layers which can be removed and added if hot or cold. I also always wear gloves and a woolly hat as a lot of body temperature is lost through your head.
Hot water bottle: Yes, a hot water bottle, putting this in the sleeping bag prior to getting in. This is bliss, especially if you have cold feet from the day, I find keeping your feet warm keeps your body warm.
Water and Food: Make sure you have plenty of water to boil and food that can be cooked. You cannot beat a hot cuppa tea and a toasted sandwich on a cold day.
A towel: As the floor of the bivvy is cold, I always put a folded towel on the floor where my feet go, when I get out of the bed creating a little warm area for my feet to be on.
Bed: Store all your bags and non-used items under your bed as this will create a barrier between the cold floor and the underneath of the bed keeping the underneath getting cold and transferring it through to you as you sleep.
Second set of Clothes: I always carry a second set of clothes in case of rain. Even though I have wet weather clothes I always carry a second set as if I get wet, I changed to dry clothes, wet ones will only get cold.
Flask: Fill a flask prior to going to sleep, if you wake up you have hot water for a drink without waiting a kettle to boil.
Car: If you get cold and cannot warm up, reel in the rods, and go turn on the engine for a while to warm up.
Go home: If all else fails and you are extremely cold, do not be a hero go home. The fish will be there for the next session.
Safe fishing guys and girls remember it is not carpy to be dead.