Heat stress, explained.
Plain-language guides to the numbers that actually measure heat danger — and how to stay safe when it climbs.
What is wet-bulb globe temperature (WBGT)?
The complete heat-stress measure — how it's built, how to read the danger levels, and why it's the standard.
WBGT vs. heat index: what's the difference?
Heat index is shade-only; WBGT adds wind and sun. Which to trust, and when.
How accurate is this WBGT — and how do we know?
A live WBGT is a model. How we check ours against the NWS, find the conditions it runs warm or cool, and correct it — proven on cities it never saw.
Is it too hot to walk my dog?
The air temperature isn't the number that matters — the ground is. What burns paws, and when.
Why pavement stays hot after sunset
The air cools at sunset; the ground doesn't. Why evening walks catch people out.
Why 87 °F can be more dangerous than 105 °F
A humid 87° can be harder than a dry 105°. Why humidity, not heat, decides.
Acclimatization: why the first hot week is the most dangerous
The hottest day isn't the most dangerous — the first hot week is. What adapts, and how fast.