June 8, 2012

What is heat stress and how can you prevent it? This is a crucial question for employers who want to protect their employees from the dangers of working in the heat. In a BLR webinar titled "Heat Illness: How To Keep Your Workers Safe and Productive When the Mercury Rises," Don Dressler, Sheilaja Mittal, and Gil Molina outlined answers for us.

Heat Stress: What is it?

Heat stress (also known as heat illness), Mittal tells us, "is actually not one illness, but a group of different illnesses that are all related to the body's inability to cope with the heat. They range from a heat rash all the way to heat stroke (obviously in increasing severity)." There are five main kinds of heat stress/illness:

1. Heat rash. This type of heat stress occurs most often under clothing. It is caused by blocked sweat glands. Sweat contains salt, which irritates the skin, leading to inflammation and itching around the pores.
2. Heat cramps. This type of heat stress typically occurs in the arms or legs in conjunction with physical labor. It can be caused by the loss of electrolytes from sweating. The cramps are painful, involuntary muscle contractions that occur after exercise or working in a hot environment.
3. Fainting or heat syncope. Fainting can occur when a person is not used to heat or is not well acclimatized. It is caused by decreased blood flow to the brain due to blood collecting in the legs and skin. Symptoms of heat syncope include nausea, weakness, sensation of "blacking out" and dizziness.
4. Heat exhaustion. This is a more serious effect of heat stress. Heat exhaustion is usually caused by a salt deficiency due to sodium lost in sweat. This leads to decreased fluid and blood volume. A person suffering from heat exhaustion may have a body temperature of 100°F or greater, and their blood pressure is likely to be low. Signs and symptoms include headaches; dizziness, light-headedness, or fainting; weakness; mood changes, irritability or confusion; feeling sick to the stomach and/or vomiting; extreme sweating; decreased and dark-colored urine; pale clammy skin; and a rapid pulse.
5. Heat stroke. This form of heat stress can be fatal and needs immediate medical care if spotted. Signs and symptoms include dry, pale skin, with sweating likely to be absent; constricted pupils; low blood pressure; nausea and vomiting; hot, red skin that may look like a sunburn; irritability, confusion, and incoherent language; seizures or fits; collapse or inability to respond; and a high temperature (104°F or higher). Mittal reminded us that "106 is when the person could actually die from that temperature," so recognizing these signs is crucial to get help in time.

Heat Stress: How Can You Prevent It?

• Acclimatization is a key to keeping safe. Anyone working for the first time under heat stress will develop signs of strain such as a high body temperature, or a pounding heart. On each succeeding day, their work ability increases. Give employees the opportunity to adjust to the temperature over time before reaching maximum output.
• Water needs to be consumed frequently. Per California OSHA rules, for example, you should provide enough fresh water so that each employee can drink at least one quart per hour and encourage them to do so.
• Shade is needed to provide somewhere to cool off. California OSHA rules again give us guidance: you should provide access to shade and encourage employees to take a cool-down rest in the shade. They should not wait until they feel sick to cool down.
• Training employees and supervisors is the next key prevention item. They should be trained in signs of heat stress and emergency procedures and prevention. California OSHA guidelines advise that you should train them on:
  • The environmental and personal risk factors for heat stress, such as the added burden of heat load on the body caused by things like exertion and clothing choices.
  • The importance of frequent consumption of small quantities of water.
  • The importance of acclimatization.
  • The different types of heat illness, along with common signs and symptoms of each.
  • The importance of immediately reporting signs/symptoms of heat stress/illness to a supervisor. (This is for signs in themselves or from a coworker).
  • The employer's procedures for responding to possible heat illness (what procedures to follow when an employee exhibits symptoms), including how emergency medical services will be provided should they become necessary.
  • The procedures for contacting and directing emergency medical services to the worksite.
  • The employer's procedures, if necessary, for transporting employees to a point where they can be reached by an emergency medical service provider.

Even with everyone trained, employees must also know their roles. The employer must designate someone to be available to invoke the emergency procedures when necessary.

For more information on preventing heat stress, order the webinar recording. To register for a future webinar, visit http://catalog.blr.com/audio.

Don Dressler of Don Dressler Consulting of Irvine, California, (www.dondressler.com), has been working with heat illness safety for over 15 years.

Sheilaja Mittal, MD, QME, MRO, is the Medical Director for WorkWell Medical Group. (www.workwellmedical.org) She has an extensive medical perspective for identifying signs of heat illness and how to respond when the first signs of heat stress begin.

Gil Molina is CEO of the California Association of Agricultural Labor. (www.caalag.org) Molina is a former U.S. Department of Labor Wage and Hour Investigator.