Solution Summary: Arm Immersion Cooling System
Providing an arm immersion cooling system for workers at a cooling station is an administrative control that can help prevent health problems from heat and sun exposure. This system consists of a trough for cool or cold water at or above waist-level for users to immerse their hands and forearms to reduce body heat. There is a thermometer and a guide for how long to continue the immersion that is based on the temperature. Thus, the immersion cooling system enables workers to lower core temperature and potentially prevent the onset of heat-related illness.
Figure 1. First Line Technology ICE. (Photo courtesy of First Line Technology)
The longetivity of immersion will be depedent on the temperature of the water in the trough. Thus, ICE also provides a guide for temperature and immersion time for core temperature cooling (figure 2).
Figure 2. Instructional guide printed on ICE for temperature and immersion time. (Photo courtesy of First Line Technology)
How Risks are Reduced:
The Immersion Cooling Equipment enables the user to rapidly cool his or her body. This is most effectively done when the user’s forearms and hands are fully submerged in ice water. Heat is transferred from the body to the ice and water in the system through convection and conduction. Using ICE optimizes the cooling effect and successfully lowers core temperature, which will also lower heart rate and blood pressure.
Depending on the size and surface area of the extremity immersed, a 2013 study has shown extremity cooling can lower body core temperature from 0.2 to 1.0oC in 10 minutes versus control conditions. Arm immersion up to the elbows resulted in reduced cardiovascular strain by lowering heart rate 10 to 25 beats per minute and increasing work tolerance 60% (DeGroot et al., 2013).
Jean Christophe Le, MPH - CPWR The Center for Construction Research and Training