Chapter 2-3 Proper Body Temperature

Sources & Resources FM 3-05.70 FM 21-76 SAS Survival Guide Air Force Pamphlet 36-2246

Course Overview Unit 1 – The Elements of Surviving Unit 2 – Personal Protection Unit 3 – Necessities to Maintain Life Unit 4 – Orientation and Traveling

Unit 2 Personal Protection Basic Survival Medicine Plants for Medicine Proper Body Temperature Clothing Shelter

How ready are you to learn today? Not very ready.. I forgot my warm coat! A little slow to get going... I forgot to brush my teeth this morning? Good to go... I am ready for winter! I am focused, I binged watched Naked and Afraid this weekend! 30

Chuck Norris Moment of Inspiration AS-400 Survival Chuck Norris Moment of Inspiration If you have five dollars and Chuck Norris has five dollars, Chuck Norris has more money than you When the Boogeyman goes to sleep every night, he checks his closet for Chuck Norris. There is no theory of evolution. Just a list of creatures Chuck Norris has allowed to live. His record, based on tournament matches, is estimated to be 183-10-2, though some sources list it as 65-5. Norris won an estimated 30 or more tournaments, beating an average of five opponents per tournament. At the New York tournaments, he defeated 12-13 opponents per tournament.

Most hypothermia deaths happen between ___ and ______ degrees. 10 & 20 30 & 50 0 & 32 -20 & 0 30

Overview Chapter Objective Know the proper body temperature. 2. Samples of Behavior/Main Points a. List the factors causing changes in the body core temperature. b. Describe the result of exposure to extreme temperatures. c. Define dissipate. d. Describe the effects of wind on the body. e. Describe the effects of moisture on the body. f. List five ways body heat can be transferred. g. Define radiation, conduction, convection, and evaporation. h. Understand Wind Chill

Body Temperature I. Body Temperature. The body functions best when core temperatures range from 96ºF to 102ºF. Preventing too much heat loss or gain should be a primary concern for survivors. A. Climatic Conditions. Factors causing changes in body core temperature are the climatic conditions of temperature, wind, and moisture. 1. Temperature: As a general rule, exposure to extreme temperatures can result in considerable decreases in physical efficiency. 2. Wind: Increases the chill effect and causes dissipation of heat, and accelerates loss of body moisture. 3. Moisture—Precipitation, Ground Moisture, or Immersion. Water provides an extremely effective way to transfer heat to and from the body.

Exposure to extreme temperatures results in considerable _________ in physical efficiency. increase decrease output work load 30

Heat Transfer B. Heat Transfer. There are five ways body heat can be transferred. They are radiation, conduction, convection, evaporation, and respiration. Radiation It is defined as the transfer of heat waves from the body to the environment and/or from the environment back to the body. Radiation is the primary cause of heat loss. a. For example, at a temperature of 50ºF, 50 percent of the body’s total heat loss can occur through an exposed head and neck. As the temperature drops, the situation gets worse. b. At 35ºF, the loss can be 75 percent under the same circumstances. Not only can heat be lost from the head, but also from the other limbs of the body. c. The hands and feet radiate heat at an exceptional rate due to the large number of capillaries present at the surface of the skin. d. These three areas (head, hands, and feet) of the body must be given particular attention during all periods of exposure to temperature extremes.

Heat Transfer 2. Conduction is define as the movement of heat from one molecule to another molecule within a solid object. a. Extreme examples of how heat is lost and gained quickly are deep frostbite and third-degree burns. b. Heat is also lost from the body in this manner by touching objects in the cold with bare hands

Heat Transfer 3. Convection. Heat movement by means of air or wind to or from an object or body is known as convection. a. The human body is always warming a thin layer of air next to the skin by radiation and conduction. The temperature of this layer of air is nearly equal to that of the skin. b. The body stays warm when this layer of warm air remains close to the body. However, when this warm layer of air is removed by convection, the body cools down. c. A major function of clothing is to keep the warm layer of air close to the body; however, by removing or disturbing this warm air layer, wind can reduce body temperature. d. Wind can provide beneficial cooling in dry, hot conditions, or be a hazard in cold, wet conditions.

At 50ºF, ____ percent of the body’s total heat loss can occur through an exposed head and neck. 75 50 25 90 30

Heat Transfer 4. Evaporation: is a process by which liquid changes into vapor, and during this process, heat within the liquid escapes to the environment. a. An example of this process is how a “desert water bag” works on the front of a jeep while driving in the hot desert. The wind created by the jeep helps to accelerate evaporation and causes the water in the bag to be cooled. b. The body also uses this method to regulate core temperature when it perspires and air circulates around the body. The evaporation method works any time the body perspires regardless of the climate. c. For this reason, it is essential that people wear fabrics that “breathe” in cold climates. If water vapor cannot evaporate through the clothing, it will condense, freeze, and reduce the insulation value of the clothing and cause the body temperature to go down.

Heat Transfer 5. Respiration. The respiration of air in the lungs is also a way of transferring heat. It works on the combined processes of convection, evaporation, and radiation. a. When breathing, the air inhaled is rarely the same temperature as the lungs. Heat is either inhaled or expelled with each breath. b. A person’s breath can be seen in the cold as heat is lost to the outside. c. Because this method is so efficient at transferring heat, warm, moist oxygen is used to treat hypothermia patients in a clinical environment.

Conduction Convection Respiration Evaporation Is a process by which liquid changes into vapor, and during this process, heat within the liquid escapes to the environment. Conduction Convection Respiration Evaporation 30

You should wear clothing that ______ in cold climates ? retains heat breathes is made of rubber retains body moisture 30

Wind Chill Chart

Wind Chill vs Watch Wind Chill Warning: Take Action! NWS issues a wind chill warning when dangerously cold wind chill values are expected or occurring. If you are in an area with a wind chill warning, avoid going outside during the coldest parts of the day. If you do go outside, dress in layers, cover exposed skin, and make sure at least one other person knows your whereabouts. Update them when you arrive safely at your destination. Wind Chill Watch: Be Prepared: NWS issues a wind chill watch when dangerously cold wind chill values are possible. As with a warning, adjust your plans to avoid being outside during the coldest parts of the day. Make sure your car has at least a half a tank of gas, and update your winter survival kit. Wind Chill Advisory: Be Aware: NWS issues a wind chill advisory when seasonably cold wind chill values but not extremely cold values are expected or occurring. Be sure you and your loved ones dress appropriately and cover exposed skin when venturing outdoors

Wind Chill Preparation Hypothermia is a dangerously low body temperature and is the most common winter weather killer Most hypothermia death happen between 30 and 50 degrees. If you or your clothing are wet, then hypothermia becomes even more likely.  Hypothermia Prevention Tips Stay dry. Wet clothing results in much faster heat loss from your body. Wear waterproof insulated boots. Stay covered. Wear mittens or gloves, and wear a hat. At least half of your body heat is lost if your head is not covered. Dress layered. Trapped air between loose fitting clothing helps to insulate.

Hypothermia Statement Wind Chill Watch Wind Chill Advisory The NWS issues a __________when dangerously cold wind chill values are expected or occurring. You should avoid going outside during the coldest parts of the day. Hypothermia Statement Wind Chill Watch Wind Chill Advisory Wind Chill Warning 30

The most common winter killer is? Avalanche Hypothermia Heat Stroke The Abominable Snowman 30

Most hypothermia deaths happen between ___ and ______ degrees. 10 & 20 0 & 32 30 & 50 -20 & 0 30

Chapter 2-3 Summary Chapter Objective Know the proper body temperature. 2. Samples of Behavior/Main Points a. List the factors causing changes in the body core temperature. b. Describe the result of exposure to extreme temperatures. c. Define dissipate. d. Describe the effects of wind on the body. e. Describe the effects of moisture on the body. f. List five ways body heat can be transferred. g. Define radiation, conduction, convection, and evaporation.

Next Lesson 2-4 Clothing