Hypothermia is not that uncommon in whitewater boating. Milder forms of hypothermia can even occur on a hot summer day (as many whom have paddled the Savage River and swam have discovered). Hypothermia in simple terms is when the body's core temperature drops and it doesn't take too much of a drop to cause significant problems.
Here are the various stages of hypothermia:
- Stage 1: Body temperature drops just a degree of two. You will notice that the person is shivering and may have blue lips. Take these warning signals seriously. Check the persons clothing for suitability. Provide extra insulating layers and wind protection. I really like a skull cap to add warmth really fast. If you have warm liquids like soup, tea, or coffee - offer it to the victim. If you have been sitting eating lunch, get back to paddling to get the blood flowing again. If these steps are not feasible, consider walking out with the person. Whatever you do, don't ignore these symptoms.
- Stage 2: Body temperature drops 2 - 4 degrees. This is starting to get very serious. The body in an effort to save itself shuts down blood flow to the extremities to concentrate on core protection. The muscles stop working in this stage and that means they can't even hold their paddle properly. Many start acting rather silly in this stage of hypothermia and are often totally unaware on where they are at. If someone is in this condition, they don't belong on the river - period! You need to get them dry and warm pronto. You also need to evacuate them and get them to a hospital for further evaluation. In the mean time, wrap in anything that provides significant insulation like a sleeping bag, blankets, space blanket, spare clothing, etc.
- Stage 3: Body temperature drops roughly 10 degrees. This takes some time to occur and the body basically shuts down as much as possible. Heart rate and breathing slow considerably in this stage. You must get the victim to a hospital or ambulance ASAP!
Prevention is rather simple:
- Check the weather and water temperatures prior and during the trip.
- Dress appropriately
- Dress in layers, bring spare clothing
- Look for hypothermia signals on your paddling buddies
- When paddling in cold weather, paddle at least one grade lower than your normal runs remember the 50-50 rule: if either the water temperature or the wind chill factor is 50o or lower - be prepared for hypothermia
The ACA in the Level 1 curriculum covers a couple of strategies for conserving body heat should you capsize in a large body of water and assistance is expected to take some time. The first is HELP which stands for Heat Escape Lessening Position. Basically you curl up into a ball exposing as little body surface area as possible. This is a good strategy if you are by yourself in open water which by itself is a serious lack of good judgment. The second approach is when a group of boaters have capsized near each other. This strategy is called HUDDLE which is self-explanatory. Think of this as a group hug and you are keeping each other warm and can talk to each other. These strategies and other useful information are in the following ACA pamphlet: Safe Paddling Brochure.
Hyperthermia is the exact opposite of hypothermia, the body gets too hot. Other terms for hyperthermia is heat exhaustion (beginning stage) or heat stroke (advanced stage). This isn't as common as hypothermia in paddling but does occur (I know from firsthand experience). Initially, you begin to sweat profusely which is the bodies cooling system. Dehydration then takes place. Muscles cramps are really common and they really smart! You may get a splitting head ache, tire easily, vomit, and find your heart racing. Believe it or not, you may shiver periodically. The body is doing everything it can to drop your core temperature. You need to take care of this now! In mild forms, try rolling or use your helmet to pour water on your head. Consider taking a break and completely immerse your body in the water. Water does a great job at pulling transferring heat from the body. Take off excess clothing. By all means, start drinking - you need to replace lost fluids. Water is best but sometimes you also need to replace the salts as well. Dilute Gatorade is great at quickly replacing your vital salts. I always take a bottle with me and drink throughout the day. If the situation is serious, take the person to a hospital immediately.
- Dress suitably, clothing that aids in rapid evaporation is ideal
- Drink early and often
- Monitor your urine. Ideally, it should be clear. If it is a dark yellow, you are dehydrated.
- Consider dilute Gatorade to replace salts
- Get wet. This is a great time to practice your rolls.
- Eat lunch in the shade