Wet Bulb Temperatures? It all depends on who you ask.

Here I list paper Wet Bulb Tables, Online Calculators, and they are all different

I use these tables because they are designed for outdoor activity use in a very exposed location, and are much more extreme than others. They are designed for walk leaders and expedition leaders and are more extreme than the basic Wet Bulb Temperature math. Professor Yoram Epstien writes extensively about human physiology and heat. Hikers are not endurance athletes, and neither am I. The fact that this site is a memorial to someone who died from heatstroke while hiking in a desert is no different to hiking on the South Downs.

While I might not agree with what is happening in the Occupied Territories, this is vital information

Professor Yoram Epstein, a leading Israeli physiologist, played a crucial role in developing the Israel Defence Forces (IDF) heat safety protocols. His work established that Exertional Heat Stroke (EHS) is a function of both environmental heat load and work intensity.

Rather than standard air temperature, Prof. Epstein and IDF researchers rely on the WBGT index to quantify environmental heat stress. This metric accounts for air temperature, humidity (wet bulb), wind, and solar radiation Researchgate

Work/Rest Cycles: The IDF enforces strict guidelines that dictate the ratio of active exertion to required rest, directly scaling with rising WBGT levels.

Clothing Adjustments: When WBGT indices hit certain thresholds, soldiers are mandated to modify or reduce their uniforms (e.g., removing blouses, stripping heavy gear) to facilitate sweat evaporation. National Institute of Health

FIRST AID

Epstein and IDF medical teams pioneered the “cool and run” philosophy, which asserts that the priority for an EHS victim is rapid core-body cooling. https://www.nejm.org/doi/full/10.1056/NEJMc1909690

Immediate Intervention: If a person exhibits an altered central nervous system (collapse, irrational behaviour, loss of consciousness) and a core temperature above 40.5°C, cooling (preferably via whole-body cold water immersion) should happen immediately on-site Pubmed

Prioritising Cooling: Delaying cooling to transport the victim to a hospital drastically increases mortality rates, as the prognosis depends strictly on the duration the body stays above the critical temperature Researchgate

Long-term prognosis: An episode of EHS can lead to temporary or permanent Heat Intolerance (inability to thermoregulate adequately). This must be checked with the support of your physician or GP.

The UK MOD have a similar policy.

https://arielschecklist.com/wbgt-chart/

There are, of course, excellent alternatives:

Online Wet Bulb Calculator https://www.omnicalculator.com/physics/wet-bulb

This site includes an explanation of what wet bulb means, the math and a calculator which looks like this: