IT’S HOT OUTSIDE: HEAT EMERGENCIES

Presence Regional EMS System July 2015

Objectives

Discuss thermoregulation in the body Describe 5 ways the body can eliminate heat

in a hot environment List 3 forms of illness caused by heat exposure Using a variety of scenarios outline the

assessment findings and management of patients suffering from heat exposure

Information for this presentation drawn fromBledsoe, Porter and Cherry (2013) Paramedic Care: Principles and Practice Prentice-Hall Inc. Upper Saddle River, NJ Volume 5 4th Edition

Environment

The environment is defined as the surrounding external factors that affect the development and functioning of living beings.

Human beings depend on the environment for life but must also be protected from its extremes.

Homeostasis is the process the body uses to maintain the correct peripheral temperatures and the core body temperature.

Pathophysiology of Heat Disorders

The body gains and loses heat into the environment via the thermal gradient.

The thermal gradient is the difference in temperature between the environment (ambient temperature) and the body

If the environment is warmer than the body, heat flows from the environment into the body

Thermogenesis

How does the body generate heat??? Work induced thermogenesis from exercise Sugar breakdown in the cell – 60% of energy

generated lost as heat Epinephrine can increase the rate of sugar

breakdown and increase heat generation.

Thermolysis The body loses heat into the environment

from: Conduction – direct contact with a surface

Sitting in a chair transfers heat to the chair Convection – air currents passing over the body

Breezes or fanning the body Radiation

A warm body radiates heat into a cooler environment Evaporation

Water or sweat changes from a liquid to a vapor removing energy/heat from the body

Respiration Exhaling water vapor combines convection, radiation

and evaporation to remove heat

Mechanisms of heat loss

Core Temperature

The body’s core temperature deep in the tissues does not vary much from 98.6° F. This is the most efficient temperature for the chemical reactions in the cell.

The body’s core temperature is controlled by the hypothalamus in the brain stem.

When the hypothalamus senses a rise in core temperature it directs the body systems to decrease heat production and increase heat loss.

Heat Control

Decrease heat production Feeling lethargic and lazy Rest

Increase heat loss Sweating Vasodilation – moving blood

from the core of the body tothe periphery

Increase exhalation Fanning Loose clothing Craving cold drinks

Peripheral Temperature

The outer shell of the body is more tolerant of temperature extremes than the core.

The outer shell can manage temperatures of from 0° F to 120° F for short periods of time and still maintain a normal internal core temperature.

Who Is At High Risk?

Not everyone is equal when it comes to tolerating heat.

Who Is At High Risk?

Extremes of Age: geriatric and pediatric populations

Health of the Patient: diabetes, heart disease

Medications: beta blockers, diuretics, antihistamines, psychiatric medications

Level of Acclimatization: how adjusted is the individual to this type of weather

Exposure

Length of exposure Intensity of exposure Environmental Factors: Wind and

Humidity

Heat Index

It’s not the heat, it’s the humidity. The Heat Index factors in both heat and

the relative humidity to provide information for problems related to the duration of exposure.

The higher the humidity, the less able individuals are to tolerate heat.

Preventative Measures

Preventing Heat Disorders is easier than treating them: Maintain adequate fluid intake. Thirst is a poor indicator of hydration. Allow time to get used to hot environments before spending long periods being active in the heat. Limit exposure to hot environments

Special Situations

Situations which might result in heat illness without extremes of ambient temperature Industry Elderly Extreme exertion inmoderately warm weather Heat without an environment of moving air.

Heat Illnesses

The main Heat Illnesses are: Heat Cramps Heat Exhaustion Heat Stroke

Complicating factors: Dehydration Loss of sodium and other electrolytes Failure of thermoregulation systems

Heat cramps are the least serious form of heat illness

Muscular cramps or spasms. Result from the loss of too much salt

through perspiration. Adequate intake of water with

insufficient intake of salt

Heat Cramps

Heat Cramps

Normal level of consciousness, mentally alert

May feel dizzy or faint Vital signs normal Core body temperature normal or near

normal Peripheral body temperature warm and

moist

Heat Cramps Management Remove the patient from the hot

environment Administer water with salts added

Sports drinks Water with ¼ tsp of salt per quart NO SALT TABLETS!!

Moist cool towels to cramped areas Advise patient to avoid exertion for 12 hours. Transport may be warranted only if the

patient desires or has other associated symptoms or conditions.

ALS: consider IV bolus of NS.

Caused by blood pooling in dilated vessels just below the skin.

Complicated by loss of salt and water through sweating. Loss of 1-2 liters of water per hour Loss of 20-50 mEq sodium per hour

Heat Exhaustion

Heat Exhaustion

Signs and symptoms of dehydration and hypovolemic shock

May have altered level of consciousness if poor perfusion to brain

Rapid shallow respirations Weak pulse Low/normal blood pressure Core temperature normal Skin pale, cool, sweaty

Heat Exhaustion Management

Remove the patient from the hot environment.

O2 and ventilation as needed. Remove and/or loosen clothing. Apply cold, wet compresses and/or fan the

patient lightly. Shock position. Do not give the patient fluids by mouth if he

has a decreased mental status or is nauseated or vomiting.

ALS: consider IV boluses of NS at 20 ml/kg. Transport to ED for further care

Heat Stroke

Life-threatening emergency in which the ability of the body to dissipate heat is completely lost.

Loss of normal thermoregulation Extremely high core temperatures The high body temperature damages and

destroys cells of the brain, heart, and kidneys, leading to permanent disability and death of the patient.

Heat Stroke

Altered level of consciousness (confused, unconscious)

Altered central nervous system Seizures, headache, psychosis

Cessation of sweating Hot dry skin Very high core temperature (102° F +++) Shallow, slow respirations Slow pulse Low blood pressure

Management of Heat Stroke

Remove the patient from the hot environment. Support oxygenation and ventilation as

needed. Remove and/or loosen clothing. Actively cool by pouring cool water over the

patient . Wrap the patient in a wet sheet. Aggressively fan the patient. Ice and cold packs are not recommended

as they can cause shivering and increase the temperature.

Monitor body temperature to avoid accidental hypothermia

Heat Stroke Management

Watch for and manage seizures should they arise.

ALS: establish IV and initiate fluid boluses of NS as long as lungs remain clear.

Immediate transport indicated

Review

Answer the following questions as a group.

If doing this CE individually, please e-mail your answers to:

shelley.peelman@presencehealth.orgUse “July 2015 CE” in subject box.

You will receive an e-mail confirmation. Print this confirmation for your records, and document the CE in your PREMSS CE record book.

IDPH site code: 067100E1215

1. Which of these Risk factors predispose individuals to environmental emergencies? (Pick all that apply) 

A. Pediatric patientsB. Geriatric patientsC. People in poor healthD. Eating hot spicy food such as tacos and Indian

food within 3 hours of exposureE. FatigueF. Certain medications such as diuretics and beta

blockersG. Existing medical conditions

2. The area of the brain responsible for controlling thermoregulation in the body is:

A. the ponsB. the cerebellumC. the hypothalamusD. the limbic system

3. Bill, who is 20 years old, is working construction this summer over school break. At his first day of work, he is has neglected to drink enough water or take in enough salt to account for his losses due to sweating. What uncomfortable condition is Bill likely to experience: 

A. heat exhaustionB. hyperthermiaC. heat strokeD. heat cramps

4. What treatment would be of help for Bill? ( Pick all that apply)

A. Remove him from the hot environmentB. Have him drink a sports drink over an hourC. Have him gulp down large amounts of ice

waterD. Keep him covered with warm blankets to

prevent heat loss

Ed is 85 years old. He always helps carry the flag for the American Legion Color Guard in the 4th of July parade. It is 1200 hours and Ed is about halfway through the parade. He is dressed in the blue wool dress uniform of the American Legion. The day is sunny with a temperature of 88° F with 85% humidity. A slight breeze is blowing. Suddenly Ed gets weak and shaky. He staggers to the side of the street and sits down on the curb. You are called to help Ed.

5. Why is Ed at high risk for a Heat Related Illness? (Pick all that apply)

A. Elderly B. Possible existing medical conditions and

medicationsC. Dressed too warm for the environmentD. Inadequate intake of fluids

6. Ed is awake but slow to respond. His airway is open and his respirations are unlabored at a rate of 16. His pulse is fast at a rate of 104 and his skin is pale, cool and sweaty. His BP is 90/60. His chest and abdomen are warm but not hot to touch. What is wrong with Ed?

A. heat exhaustionB. hyperthermiaC. heat strokeD. heat cramps

7. Which of these treatments will help you manage ED in the field? (Pick all that apply)A. Oxygen to an O2 sat of 94%B. Remove from the heatC. Remove heavy clothingD. Rapid cooling with ice packsE. IV of Normal Saline at 20 ml/kgF. Adenosine 6 mg IVG. Sips of 3.3% saline to drink if Ed is not

nauseatedH. Sips of a sports drink if Ed is not nauseated

Maude is 90 years old and lives alone. She does not like to run the air conditioning in her house and keeps the windows closed at night because she is afraid. It is about 2000 hours on an August evening. It is about 90º F out all day with 90% humidity. It is currently about 83º F out. Maude’s neighbor has called 911 because she has not seen Maude for 24 hours.

Maude’s doors are locked. You can hear the Television playing and hear a dog barking on the other side of the door. The police are called to break in the house.

Once the door is open you feel a hot blast of air from the house and it smells of body fluids.

You find Maude seated in a recliner in front of the television dressed in a pink sweat suit with an afghan over her legs.The thermostat in the house reads 90º F.

Maude is not responsive and does not respond to shake and shout.

Airway: No noises with breathing Breathing: Very slow and shallow.

Poor rise and fall of the chest.  Circulation: Skin color very red. Very hot and dry to touch. Radial pulses irregular, weak and very slow

Focused PhysicalVital Signs: Pulse 60 and irregular Respirations: 6 and shallow BP: 70/50 Pulse Oximetry: 85% Blood Sugar: 300 

Head and Neck: Face is very red and hot. Pupils react sluggishly. No saliva noted. Mouth and lips are very dry. Lips purse out with exhalation. Jugular veins are flat.Chest: Breath sounds: slight rales in bases. Skin hot to touch.

Abdomen: Hot to touch. No distention or gross abnormalities.  GU: Maude has been incontinent of

urine.  Extremities: Hot and dry. No pulses. When you move her she moves only her left arm and leg and not her right. She tries to pull away from you, weakly.

No one is able to give a history other than Maude is old, but she does OK on her own.

8. What is wrong with Maude? A. heat exhaustionB. feverC. heat strokeD. heat cramps

9. What made Maude at high risk for this problem? (Pick all that apply)

A. AgeB. Exposure to heat without cooling or air

movementC. Dehydration D. Possible medical conditions

10.What has happened to Maude? (Pick all that apply)

A. Her body has become dehydrated.B. She has overwhelmed the thermoregulation system of her body.C. Her body temperature is so high that cell

death in organs such as the brain has occurred

D. She is suffering from results from exposure to pathogens and infection.E. She has had a stroke and was unable to move or cool herself.

11. How do you want to manage Maude?

A. Remove her from the house and out into the cooler air outdoors

B. Remove her clothes and wrap her in a sheetC. Soak the sheet with waterD. Apply cold packs to her armpits and groin.E. Support oxygenation and ventilation to an O2 sat of

94%F. IV of Normal Saline at 20 ml/kgG. Atropine 0.5 mg IV to raise the pulseH. Sips of a sports drink if Maude is not nauseatedI. Monitor her temperature and avoid hypothermia

12.How well will Maude do after this incident?

A. She will be fine in a few hours when she is cooler.

B. She will probably not survive this heat illness.

Answers

1. A,B,C,E,F,G 11. A,B,C,E,F,I2. C 12. B3. D4. A,B5. A,B,C,D6. A7. A,B,C,E,H8. C9. A,B,C,D