Second is that when you are wearing hiking clothing for warmth, you are not trying to be as warm as possible but to reach a thermal equilibrium i.e. a state in which your heat production roughly balances your heat loss so that you remain within your comfort zone whether you are on the move, on the move and sweating, sitting still and sitting still and sweating.

To achieve this thermal equilibrium under changing conditions your hiking clothing has to be versatile. Of course you can make adjustments to your hiking clothing by taking off layers when it gets too hot and putting more on when it gets cold but in most cases it’s both inconvenient and impractical.

The hiking clothing you use needs to be able to handle all the different situations, whether on the move or sitting still, at the same time. They need to be able keep the still and dry air to insulate you, keeping you warm and when you’re moving allow the vapor of your sweat to pass through and escape to keep you cool.

If your hiking clothing absorbs some of the moisture so that when you sweat heavily it remains damp, they lose the ability to keep you warm as it has lost its ability to hold dry air which acts as an insulating layer and at the same time your body will continue to draw latent heat from your body needed to turn the sweat into vapor.

The result is that you suffer from what is called the after-exercise chill. Experiments have shown that with an absorptive material the chill can last for about two hours but with a non-absorptive material like fibre-pile the chill is negligible.

The Three-Layer Hiking Clothing System

The ability to prevent after-exercise chill so well is what makes the three-layer hiking clothing system so popular. It’s a proven way to ensure your comfort outdoors. Each of the three layers have different functions that work together to cope with the different conditions.

The First Layer

Moisture management is the main function of the first layer. Some experts call it the next-to-the skin layer. It keeps you cool in the summer and keeps you warm in winter by keeping you dry.

Made of some sort of polypropylene or other synthetic fabrics, the fabric ‘wicks’ away the moisture from the skin very rapidly by capillary action dispersing it to the outer surface where it can evaporate.

The Second Layer

The second layer or middle layer of hiking clothing is the insulating layer. Their main function is to trap air, which is a good heat insulator, so you retain warmth.

This layer is made of natural fibers or fleece. Both are reliable in keeping you warm but natural fibers have a more efficient warmth-to-weight ratio and are highly compressible. Its drawback is that it has to be kept dry to maintain its ability to retain warmth.

Hiking clothing made from fleece are lightweight, breathable and insulate even when wet. They also dry faster and the warmth-to-weight ratio is even higher than wool. Fleece is very popular with many experienced backpackers I know of even when it is not as compressible as natural fibers.

The Third Layer

The third layer is the waterproof shell that both acts as a windbreaker and a rain jacket. If the outer layer doesn’t do what it’s supposed you’ll end up losing a lot of heat as the wind and penetrate into the inner layers.

It is usually made of Gore-Tex that also offers breathability. This layer of hiking clothing needs to have proper ventilation or else perspiration can’t evaporate but instead condenses on the inside of your shell.

Some picnics can take quite a bit of planning, such as an out door wedding reception, while others might be as simple as feeding the kids lunch as they sit on a picnic blanket in their back yard.

When I was a kid my grandma used to pack a picnic basket and we would go to Lake Michigan during the summer. Grandma would not take off her sensible black shoes as we walked across the sand. After spreading the blanket she would sit and watch me splash in the water and make sand castles. There always seemed to be other kids around when we had our picnic lunch and Grandma always had enough sandwiches for everybody.

If it rained my grandma would still pack a basket and we would eat on our covered front porch and play cards. If my friend from across the street came over she would share our lunch and play cards with us. The great thing about picnics is that they are flexible and adaptable to any type of weather throughout the year.

Most Sunday afternoons in the summer our family would go swimming or to a wayside area where there was enough room for my father and brothers to hit a baseball without worrying about breaking our neighbors windows. In the fall we liked to hike though one of the state parks in the splendor of red and gold leaves.

Wherever we went, Mother never packed food we would not have eaten had we been home. It just tasted better and it was more fun to play, eat when we were hungry, and play or explore some more.

My mother emptied the ice trays to pack ice around the food in her open wicker picnic basket so it would not spoil on hot summer days. Keeping food cool is not a problem today with insulated picnic baskets, backpacks and totes.

While Memorial Day is the traditional kick off to the summer outdoor grilling season and Labor Day the end, the picnic season actually goes on all year long and not just in warmer climates.

There are as many tailgating picnics in the northern states during football season, college and pro, as in the warmer southern states. Delicious smells and billowing smoke rise above the parking lots where fans are grilling their favorite foods and enjoying the camaraderie.

In the winter it has to be cold enough before people can stake out their place on a frozen lake, cut a hole in the ice and fish. A lot of the fun comes from sharing picnic food and beverages with friends while waiting for the fish to bite.

Picnic are for all seasons and all occasions from simple to elegant, impromptu to planned. There is always another picnic to look forward to anytime of the year.