Sensors can read your sweat and predict overheating. Here's why privacy advocates care

abcnews.go.com:

As global temperatures rise and summer months bring record high temperatures, employers are exploring wearable technologies to keep workers safe

On a hot summer day in Oak Ridge, Tennessee, dozens of men removed pipes, asbestos and hazardous waste while working to decontaminate a nuclear facility and prepare it for demolition.

Dressed in head-to-toe coveralls and fitted with respirators, the crew members toiling in a building without power had no obvious respite from the heat. Instead, they wore armbands that recorded their heart rates, movements and exertion levels for signs of heat stress.

Stephanie Miller, a safety and health manager for a U.S. government contractor doing cleanup work at the Oak Ridge National Laboratory, watched a computer screen nearby. A color-coding system with little bubbles showing each worker's physiological data alerted her if anyone was in danger of overheating.

“Heat is one of the greatest risks that we have in this work, even though we deal with high radiation, hazardous chemicals and heavy metals,” Miller said.

As the world experiences more record high temperatures, employers are exploring wearable technologies to keep workers safe. New devices collect biometric data to estimate core body temperature — an elevated one is a symptom of heat exhaustion — and prompt workers to take cool-down breaks.

The devices, which were originally developed for athletes, firefighters and military personnel, are getting adopted at a time when the Atlantic Council estimates heat-induced losses in labor productivity could cost the U.S. approximately $100 billion annually.

But there are concerns about how the medical information collected on employees will be safeguarded. Some labor groups worry managers