Brisk spring morning air nips at my nose and cheeks conjuring a bright red glow reminiscent of old St. Nick. A humid breeze blows from the still snow-packed mountainside above me and down through bare trees. Sunlight breaks and begins to warm the dark colors of the nylon hammock pulled around me, let the convection begin. A good morning roast is always a welcome conclusion to the surrounding blanket of a chilled night. Atop my down filled mattress and beneath my down filled sleeping bag I nestle in comfortably with only my face showing any impact of the frigid nighttime sky.
Camping in my hammock is one of my favorite pastimes. Rather it is weekend trips searching for Spanish treasure, afternoon naps in the backyard, or the long haul over several days, this simple piece of equipment known as the camping hammock has become a true friend and ally. Living in Utah and having a diversity of not only terrain but weather at any given time of the year I have to be prepared. One of the most common questions I get is about warmth and camping in winter, late fall, and early spring.
First of all, let me say that there is no right or wrong way. What works for you, keeps you comfortable and warm, and will meet the needs for your camping style will be the correct answer. I am going to share with you a few things I have tried, a couple observations, and what I personally use now. I will say, like camping on the ground, your camping hammock will be subject to the same laws of insulation.
Insulation slows heat loss using bulky and lightweight materials. Insulation performance is measured in R-values. Bulky insulation effectively traps dry air. Still air conducts heat poorly. Thus, bulky materials catching significant amounts of air significantly reduce the ability for heat to be transferred. This is best explained when thinking about a sleeping bag. The fluffy part on top of your sleeping bag keeps you warm because it is filled with still air. The flat squished part beneath you has little air and thus you feel the cold ground.
Your hammock has a few options. Underquilts, self-inflating pads, closed cell pads, and other matted fabrics are all used as insulation in hammocks. Each tends to have its own list of pros and cons. Use your conditions as well as your camping plan to find a preferred solution. Consider weight, insulation value, and sleeping comfort when making your decision. A trial run or two in the backyard is always a good idea.
An attractive option is an underquilt. Under quilts are lightweight devices that provide insulation beneath your hammock. They come in many sizes, shapes, colors, and with varying insulation choices. Underquilts are as they sound, a quilt that hangs under your hammock. They attach with a small shock cord and provide insulation and wind protection. Because of their ability to move with the underside of the hammock, the underquilt stays fluffy and maintains its insulation value. They are a one trick pony and used underneath your hammock only.
Another of the popular options are camping pads. Self-inflating or closed cell can each be used. These items lay inside the hammock directly underneath the camper. Since they do not move freely, they are more subject to losing insulation value. They have the benefit of use on the ground and in other camping scenarios. Pads also add structure and support for the sleeper.
My personal preference is the Exped down the mat. It is a down filled air mattress made specifically for backpacking. It has the highest R-value amongst pads and the added benefit of being inflatable to my desired firmness. As with other pads, it can also be used on the ground on other campouts where my hammock may not be functional. It is on the heavy side when compared to other pads and underquilts.
Borrow a couple of pads or an under quilt from a friend and find your preferred solution. If you have a rectangle sleeping bag and a couple of bungee cords, you can put together a makeshift under quilt. Your homemade contraption will work in the backyard well enough to give you an idea as to function and help inform your preference, but I would not recommend packing this into the backcountry.
In extreme cold, I have used an underquilt in combination with my Exped and a hanging tarp. While this article merely scratches the surface of the subject, you should have enough information to begin experimenting, and that is half the fun. Use your imagination, pay attention to the weatherman, and most of all have fun in the outdoors!
P.S. - Don't forget a good book.