DISCLAIMER: The following information is not intended, nor should it be assumed to be, a substitute for formal training in First Aid treatment and procedures. This information is presented to raise awareness of some medical conditions which can arise on canoeing, camping or hiking trips so that participants may better prepare themselves for all eventualities. The information presented is not intended to replace advice or instructions given by trained professional medical personnel. Information herein is gleened from various professional medical resources including the US Navy On-line Hospital web site, the American Red Cross web site and other reliable resources. It must be realized that improper or inadequate treatment of injuries can result in damages that sometimes are greater than doing nothing at all. Whenever possible and practical the assistance of trained, professional medical personnel should be summoned to administer treatment for serious injuries. The nature of outdoor recreation is such that injuries sometimes occur in remote areas far from available professional assistance. The information in this section is intended to be a helpful guide for treatment of injuries in such cases when getting professional help is not immediate and the nature of the injuries requires prompt attention. Marc McCord is not a trained medical practitioner, and makes no claim of expertise in treatment of injuries. Marc McCord and Southwest Paddler are not responsible for improper treatment of injuries and resulting damages that may occur.
On a global basis heat-related illnesses are a major cause of preventable injury and death. Due to the nature of paddlesports heat-related injuries are quite common, especially where paddlers are running cold water in warm weather and wearing wetsuits, drysuits or Goretex (tm) clothing that repel water and trap body heat. It is important to know the types of heat-related injuries that can occur, how to recognize the onset of these problems and what to do to effectively prevent them, treat them and forestall serious injury or death.
The major illnesses are heat exhaustion and heat stroke, generally caused by electrolyte loss, dehydration and a failure of the body's temperature regulatory system, which should kick in automatically to vent excess core heat and prevent heat-related problems. However, there are several other heat-related illnesses, some or all of which can and will presage the onset of the two more serious injuries. These include heat cramps, hyperthermia and a host of similar symptomatic signs of impending heat exhaustion or heat stroke.
Heat-related illnesses occur in young and old alike, though usually for completely different reasons. Paddlers risk heat-related injuries when running rivers in hot, humid conditions where solar exposure, outside air temperatures, high humidity and lack of adequate fluids intake combine to affect the active body. This is complicated by the wearing of wetsuits, drysuits or other insulating garments that do not allow radiated or evaporated body heat to escape. Heat exhaustion is an acute heat-related injury characterized by hyperthermia caused by severe dehydration. Whenever environmental and/or bodily regulatory mechanisms fail and prevent the dissipation of heat the body is in jeopardy of heat exhaustion.
Prolonging a hyperthermic condition can lead to heat exhaustion. Left untreated, that can lead to heat stroke and possibly death. The body naturally fights the effects of heat-related problems through radiation and evaporation. However, the body loses its ability to radiate heat at outside air temperatures of 95° F, at which time only evaporation remains as a means of venting heat from the body's core. Wearing protective river gear can, and often does, prevent effective evaporation while trapping escaping heat on the skin's surface and insulating the body from cooling conditions. The National Oceanic and Atmospheric Administration (NOAA) estimates that nearly 200 Americans die each year from heat-related problems, and that number increases to around 1,500 deaths during heat waves. Deaths are evenly split between males and females. Active athletes usually succomb from over exertion, while elderly people are usually the victims of excessive environmental exposure.
Heat exhaustion is characterized by weakness and fatigue, neusea and vomiting, headaches, myalgia, dizziness (increasing in severity as heat-related problems become more extreme), muscle cramps and irritability. Left untreatd, heat exhaustion can become heat stroke, characterized by central nervous system (CNS) dysfunction, bizarre behavior (like feeling cold and adding more clothing), an altered mental state including hallucinations, confusion, disorientation, coma and possibly death.
Heat-related problems can be avoided, in most cases, by minimizing exertion during periods of extreme hot and humid conditions, rehydrating frequently, resting, venting internal core temperatures by loosening clothing, getting direct air flow ventilation to the body, applying ice packs or other cold wraps and shading from direct solar exposure. Just as wind chill factors are a considerable component of coldness problems, so too must temperature humidity index (THI) factors be considered when thinking about and planning where to paddle, how long to go between rest stops and the types and quantities of fluids to drink for rehydration. Consuming alcoholic beverages in high temperature conditions will hasten fluid losses through evaporation leading to dehydration, impaired judgement and loss of physical energy and performance ability.
The author of this dissertation is not a doctor, and the closest he usually gets to one is Dr Pepper, but some links to information on heat-related problems, their symptoms, treatment and prevention are provided in the table below to help paddlers better understand the nature of heat-related illness and what can be done to prevent it, especially in areas where getting qualified medical tratment may be difficult at best to impossible at worst. It is always better to prevent medical problems than to treat them, and some common-sense preparation and practice will make paddling a lot more fun for everybody.