Heat Stress

Heat Stress• 4 Environmental Factors:

– temperature– humidity– radiant heat– air velocity

• Human factors– age

– weight

– sex

– fitness and medical condition

– acclimatization

Heat Transfer

• Convection

• Radiation

• Evaporation

How the Body Reacts to Heat

• The body first reacts to high external temps by circulating more blood to the skin. (Convection)

• Sweat is produced to help cool the body through evaporation

• If the body cannot get rid of excess heat, it will store it

Types of Heat Stress• Heat Illnesses:

– Heat Rash– Heat Syncope

(fainting)– Heat Cramps– Heat Exhaustion– Heat Stroke

• Burns– Thermal– Chemical or electrical

Heat Illnesses and Burns

• Between 1979 and 2002, 4,780 deaths occurred due to heat related illnesses*

• Between 1992 and 2006, 423 workers died in crop work alone

Source: MMWR Volume 54./No.25

Hot Temperatures are Not Just Outside!

• Laundries• Kitchens• Boiler Rooms• Trades

Controls for Heat Exposures• Engineering

Controls: ventilation, spot cooling, fans, temporary shelters shielding, equipment modifications

Controls for Heat Exposures

• Work Practices and Administrative Controls:

• changing work hours,• providing water and

fluid replacements, • more frequent rest

breaks, • acclimatization, • buddy system

Controls for Heat Exposures

• Training: recognizing signs and symptoms, preventive measures, and first aid

• PPE: light, cool clothing, cooling vests, personal cooling devices, protection from burns

• Note: CA, WA have Heat Standards

Basic First Aid for Heat Exhaustion and Heat Stroke

• Call 9-11 immediately for assistance!• Move victim to a cool, shaded area. • If dizzy or faint, elevate legs 6-8 inches• If nauseous or vomiting, lay victim on his/her

side• Loosen any heavy clothing• Unless nauseous, provide cool water every

15 minutes• Cool person by fanning or spraying cool

water. Apply wet cloths to skin.• If heat stroke is suspected, place ice packs

under armpits and groin area

Burns

Close up of second degree burn

First Aid For Minor Burns

• Cool the Burn with Cool water (not ice)

• Consider a burn cream once skin is cool and dry

• Cover lightly with a sterile gauze bandage

• Give an over-the- counter pain reliever

Sources of Information

• NIOSH publication: http://www.cdc.gov/niosh/hotenvt.html#order• NOAA Heat Index Information:http://www.nws.noaa.gov/om/heat/index.shtml• US Army Heat Stress Calculator:http://www.eustis.army.mil/weather/

weather_products/wxconversions.htm#HeatIndexCA law and information:http://www.dir.ca.gov/dosh/etools/08-006/index.htm