Labor (1) Employees (1) Symptoms (1) Refrigeration and refrigerating machinery (1) Population (1) Perception (1) Oxygen (1) Health (1) Freeze-drying (1) Consumption (Economics) (1) Cold (1) Backache (1) Liofilización (1) Salud (1) Oxígeno (1) Lumbago (1) Semiología médica (1) Frío (1) Percepción (1) Población (1) Refrigeración (1) Trabajo (1) Trabajadores (1) Consumo (1) lyophilisation (1)