When Heat Turns Deadly: What Wet-Bulb Temperature Means and Why Humidity Is the Real Killer

Person wiping sweat on a sweltering humid city street, heat haze rising from asphalt

Wet-bulb temperature is the metric that determines whether your body can survive extreme heat. New 2026 research shows deadly thresholds are being crossed now. Here is the science behind why humidity is the real killer and how to protect yourself.