High-temperature work and hot weather work
Occupational health risk warning
Flame Flame Summer Day,
In hot work and hot weather operation,
How to prevent and avoid occupational heat stroke?
Let's take a look
# 01
What are hot and hot weather jobs?
Hot work
It refers to the operation with high air temperature, or strong thermal radiation, or abnormal operating conditions accompanied by high air humidity (relative humidity ≥ 80%), and the wet-bulb black bulb temperature index (WBGT index) exceeds the specified limit, such as metal smelting, metal casting, textile printing and dyeing, glass manufacturing, etc.
Hot weather operations
High temperature weather refers to the weather with a daily maximum temperature of more than 35 °C issued to the public by the meteorological stations under the meteorological authorities at or above the prefecture and municipal level. Hot weather operations refer to the operations that the employer arranges workers to carry out in a hot natural meteorological environment during hot weather, such as field investigations, open-air loading and unloading, construction construction, sanitation operations, line inspections, etc.
# 02
Heat stroke and symptoms
Precursor to heat stroke
After working in a high temperature environment for a certain period of time, symptoms such as dizziness, headache, fatigue, thirst, sweating, palpitations, lack of concentration, and uncoordinated movements appear, and the body temperature is normal or slightly elevated but lower than 38 °C, which can be accompanied by flushing, burning skin, etc., and the symptoms can disappear after a short period of rest.
Heat stroke
An acute systemic disease caused by heat balance and/or water and electrolyte metabolism disorders and a decrease in effective circulating blood volume, with increased body temperature and/or central nervous system dysfunction and/or cardiovascular dysfunction as the main manifestations, can lead to death in severe cases.
Types of occupational heat stroke
According to the "Diagnosis of Occupational Heat Stroke" (GBZ41-2019), occupational heat stroke includes three types: heat cramps, heat exhaustion, and heat stroke.
1. Heat cramps. Engaged in physical labor or physical activity in a high temperature environment, transient and intermittent muscle spasms after heavy sweating, accompanied by contraction pain, mostly seen in limb muscles, masticatory muscles and abdominal muscles, especially the gastrocnemius muscles, symmetrical; Temperature is usually normal.
2. Heat exhaustion. Engaged in physical labor or physical activity in a high temperature environment, a group of clinical syndromes characterized by volume depletion appear, such as excessive sweating, clammy skin, paleness, nausea, dizziness, significantly increased heart rate, hypotension, oliguria, body temperature often rises but does not exceed 40 °C, can be accompanied by dizziness, syncope, and some patients only have an increase in body temperature in the early stage. Laboratory tests may show increased hematocrit, hypernatremia, and azotemia.
3. Heat stroke (including sunstroke). Engaged in physical labor or physical activity in a high-temperature environment, there are clinical manifestations mainly of significantly increased body temperature and impaired consciousness, manifested as dry and hot skin, no sweating, body temperature as high as 40 °C and above, delirium, coma and other symptoms; May be accompanied by generalized epileptiform seizures, rhabdomyolysis, and multi-organ dysfunction syndrome.
# 03
Precautions against heat stroke
Employer precautions
1. Actively improve working conditions. Priority should be given to the use of new technologies, new processes, new materials and new equipment that are conducive to the control of high temperatures, so as to reduce or eliminate the hazards of high temperatures from the source.
Set up rest places in high-temperature working environments, and rest places shall be equipped with seats, maintain good ventilation, or be equipped with heatstroke prevention and cooling facilities such as air conditioning.
Isolate workers from heat sources. Indoor workplaces can be equipped with thermal insulation devices to block the heat generated by heat sources from contacting workers, and outdoor workplaces can be equipped with devices such as simple roofs to block sunlight and reflected light from surrounding walls and floors.
2. Carry out occupational health monitoring. Organize workers engaged in high-temperature work to conduct occupational health examinations, store the results of the examinations in the occupational health monitoring files and inform the workers in writing. Before the onset of the hot season, health checks are carried out for workers working in hot weather. Workers with high-temperature occupational contraindications should be transferred from high-temperature work positions in a timely manner.
Occupational contraindications to high temperature: uncontrolled hypertension, chronic nephritis, uncontrolled hyperthyroidism, uncontrolled diabetes mellitus, systemic scar area of ≥ more than 20% (grade 8 of the work-related injury standard), epilepsy.
3. Carry out occupational health training. Popularize occupational health knowledge such as high temperature protection, heat stroke self-rescue, and first aid, and improve the ability of workers to help themselves and each other.
4. Reasonably arrange outdoor and open-air operation time. During the period of high temperature weather, the operation time shall be reasonably adjusted according to the forecast temperature issued by the meteorological station under the meteorological department at or above the municipal level.
5. Protect special populations. Pregnant female employees and juvenile workers shall not be arranged to engage in high-temperature work above level 3 as stipulated in the "Classification of Occupational Disease Hazards in the Workplace Part 3: High Temperature" (GBZ/T229.3). Pregnant female employees and juvenile workers shall not be arranged to engage in outdoor work in the open air during hot weather above 35°C, and work in workplaces with a temperature above 33°C.
6. Provide personal protective equipment and heatstroke prevention drinks and medicines. Provide workers with personal protective equipment that meets the requirements, avoid direct sunlight on their heads, and supervise and guide workers to use them correctly. Try to choose light-colored, breathable, loose material workwear of cotton and linen to speed up heat dissipation.
Provide workers working in hot and hot weather with sufficient heatstroke prevention and cooling drinks and necessary medicines that meet health standards. Money and goods must not be distributed in lieu of providing heatstroke prevention and cooling drinks.
Heatstroke prevention and cooling drinks: sugar and salt water, salt tea water, electrolyte-containing soft drinks, mung bean soup, etc.
Anti-heatstroke medicines: Ren Dan, ten drops of water, Huoxiang Zhengqi water, cool oil, normal saline, etc.
Cooling supplies: cold water and ice cubes, chemical ice packs, cold water towels, etc.
7. Do a good job in emergency rescue and drills. Formulate emergency plans for heat stroke and conduct emergency rescue drills on a regular basis, and allocate emergency rescue personnel and sufficient first-aid drugs according to the number of workers engaged in high-temperature operations and high-temperature weather operations and working conditions.
Worker precautions
1. Replenish water and electrolytes. Drink small amounts of water often to keep your body hydrated. People who work in hot environments should be appropriately supplemented with salty or electrolyte beverages.
2. Pay attention to temperature changes and make adjustments in time. Pay attention to temperature changes, understand the precautions for hot weather and work time requirements. When it's too hot, wipe your skin with a damp towel to allow the moisture to evaporate and help dissipate heat. Avoid blowing the air conditioner directly after sweating a lot, wipe off the sweat or change the sweat-soaked clothes before entering the air-conditioned room to rest.
3. Reasonable diet and nutritional supplements. Eat a light, easy-to-digest diet with plenty of fresh vegetables and fruits with high water content.
4. Regular daily life and adequate rest. Regular and adequate sleep relaxes the brain and body, which is conducive to preventing health risks such as occupational heat stroke. Do not lie down under the air vents of the air conditioner and electric fans when sleeping.
# 04
Principles of Processing
Precursor to heat stroke
Immediately get out of the high temperature environment, go to a ventilated and cool place to rest, lie down. Supplement with refreshing beverages containing salt or electrolytes and manage symptomatic conditions under close observation.
Heat cramps
Correction of water and electrolyte imbalances and symptomatic treatment.
Heat exhaustion
Physical and/or medical cooling is given, body temperature is monitored, water and electrolyte imbalances are corrected, blood volume is expanded, and shock is prevented.
Heat stroke (including sunstroke)
Rapidly reduce body temperature, continuously monitor body temperature, protect the function of important organs, support respiratory circulation, improve microcirculation, correct coagulation disorders, and provide early blood purification treatment for patients with liver and kidney failure and rhabdomyolysis.
Source: Occupational Health Division