Here are a few thoughts on preparing for the possible weather during outdoor public service events, such as the Boston Marathon, Head of the Charles Regatta, etc. which do not fall into the predictable summer weather patterns. They are based on my experience leading and instructing various outdoor activities with the Appalachian Mtn. Club and other groups.

Stay up to date on the forecast, as New England weather patterns are volatile. As none of us has the connections to change the weather, the best we can do is be prepared for it.

Generally, the sponsors will go ahead with the event, unless the weather is a clear hazard to competitors, participants, volunteers and/or spectators. Lightning, extreme heat, and cold/wet conditions are the most likely to cause cancellation. The competitors have been training during all sorts of weather for many months, and the ones traveling to Boston are already committed. All of the logistics have been arranged; materials and supplies purchased, various service providers, vendors and so on, involving planning for many months prior to the event. The number of spectators will likely be affected much more by the weather than the number of competitors.

Volunteers are even more necessary when the weather is bad, as extreme weather will mean a greater need for first aid support.

The big concern with cold damp weather is hypothermia (lowering of the body’s core temperature). Water, from perspiration or precipitation, dramatically increases heat loss to the point where the body cannot maintain its normal temperature. Immersion in cold water is even more so. Wind, often in the forecast, accelerates this process. It does not matter whether the water comes from perspiration, precipitation, or immersion.

Hypothermia is also a concern during cool dry weather, as the competitors are A) lightly dressed, B) have low body fat/less insulation, and C) have used up their body’s energy reserves. The usual symptoms of hypothermia, such as shivering, may be absent or obscured. Once they stop moving and generating heat, hypothermia can set in rapidly.

With some weather forecasts, hypothermia is also a concern for spectators and volunteers.

We cannot be of any help to others, if we need help ourselves.

A few suggestions:

1) Cotton is a poor/dangerous choice for insulation in wet or damp conditions. It holds moisture against your skin, where it increases your heat loss significantly. Much better material choices include synthetics such as polyester fleece or wool.

2) Dress in layers. This allows flexibility for varying weather, and for varying levels of exertion. As volunteers will be standing for much of the time, they will generate little heat from movement, and should have more layers than someone who is active.

3) A system commonly used by hikers and other outdoors people is to have a first layer against the skin of synthetic long underwear (often called “polypro” but is now usually various forms of polyester).

4) Over that, you will have various layers of insulation made of synthetic fleece, pile, fiberfill, or wool. Vest layers may be helpful, and it is always more versatile to have something that opens in front, rather than a pullover style. Bring extra layers in a plastic bag, in case you get soaked.