Metrosonics® Area Heat Stress Monitor The general purpose HS-32 Area Heat Stress Monitor is ideal for measuring the high humidity, temperature and radiant heat conditions that can cause heat stroke and other heat induced illnesses. This instrument is portable, simple to operate and instantly computes both indoor and outdoor WBGT. In addition, the HS-32 is extremely rugged and able to withstand rough handling and harsh environments. Picture is not representative of HS-32.