🥵 Heat: Sneakier Than Cold

The heat index (feels-like temperature based on humidity) and the three stages of heat illness, from simple cramps to heatstroke that can kill in hours without cooling.

★ At an actual 32°C, humidity alone pushes the perceived temperature from 33°C (40% humidity) to 41°C (70% humidity) — humid air prevents sweat from cooling your body.

★ Pushing yourself hard can make you lose up to 2 to 3 L of sweat per hour and about 1 g of sodium per hour: plain water without salt isn't enough to make up for prolonged exertion in the heat.

★ The landmark Bedouin study (Nature, 1980) proved that a black robe doesn't absorb more useful heat than a white one: worn loose, it creates a chimney effect that vents heat before it reaches your skin.

★ Heatstroke is recognized by mental confusion, not just feeling hot: the moment someone becomes disoriented in extreme heat, it's a life-threatening emergency.

★ Unlike heat exhaustion, untreated heatstroke kills in dozens of percent of cases without fast cooling.

14 rows

Temperature : Feels-like temperature (air) or approximate core temperature (body); N/A for heat cramps — higher is better.

38°C, 70% humidity ≈

61,5 °C

35°C, 80% humidity ≈

56,5 °C

40°C, 30% humidity ≈

43,1 °C

38°C, 40% humidity ≈

42,9 °C

32°C, 70% humidity ≈

41,1 °C

Classic heatstroke ≈

41 °C

35°C, 50% humidity ≈

40,7 °C

Exertional heatstroke ≈

40 °C

Heat exhaustion ≈

39 °C

Mild exertional hyperthermia ≈

38,3 °C

30°C, 80% humidity ≈

37,7 °C

32°C, 40% humidity ≈

32,6 °C

27°C, 90% humidity ≈

29,8 °C

Heat cramps

— °C

Sources (4)

Other numbers

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