OSHA-referenced data logging heat stress meter that calculates Wet Bulb Globe Temperature (WBGT) from ambient temperature, humidity, and direct/radiant sunlight to give a feels-like reading, with a user-adjustable audible WBGT alarm and a switchable indoor/outdoor mode. Indoor range is 32-138F (0-59C) at about +/-2.7F accuracy, while outdoor range is 32-132F (0-56C) at about +/-3.6F accuracy. Records to a removable SD card (up to 16GB) either manually or at programmable intervals from 1 to 3600 seconds, with a backlit LCD, data hold, and Max/Min, and ships with a carrying case and batteries.