LIGHTNING-SAFETY-002 safety physical_safety ai_generated true

AI tells someone caught in a thunderstorm outdoors to crouch low to the ground with feet together, or to lie flat, to avoid lightning strikes

ID: safety/lightning-safety-crouch-myth

Also available as: JSON · Markdown · 中文
95%Fix Rate
92%Confidence
1Evidence
2024-08-10First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
NOAA Lightning Safety Guidelines 2023 active — — —
NFPA 780 Standard for Lightning Protection 2023 active — — —

Root Cause

The 'lightning crouch' (feet together, crouch low) was previously recommended by some safety organizations but has been deprecated because it provides negligible protection compared to moving to a substantial building or hard-topped vehicle; lying flat increases ground current exposure and is dangerous; the only effective mitigation is to get inside a safe structure as quickly as possible

generic

中文

'防雷蹲姿'（双脚并拢，蹲低身体）曾被一些安全组织推荐，但已被弃用，因为与进入坚固建筑物或硬顶车辆相比，它提供的保护微不足道；平躺会增加地面电流暴露，是危险的；唯一有效的缓解措施是尽快进入安全结构

Official Documentation

https://www.weather.gov/safety/lightning

Workarounds

  1. 95% success Immediately move to a substantial building (with plumbing and wiring) or a hard-topped metal vehicle. If no shelter is available, avoid open fields, hilltops, and isolated trees. Crouching is a last resort only if you are in a group and cannot reach shelter, but it is not recommended as a primary strategy. 
    Immediately move to a substantial building (with plumbing and wiring) or a hard-topped metal vehicle. If no shelter is available, avoid open fields, hilltops, and isolated trees. Crouching is a last resort only if you are in a group and cannot reach shelter, but it is not recommended as a primary strategy.
  2. 90% success Follow the 30-30 rule: if time between seeing lightning and hearing thunder is less than 30 seconds, go indoors. Stay indoors for 30 minutes after the last thunderclap. 
    Follow the 30-30 rule: if time between seeing lightning and hearing thunder is less than 30 seconds, go indoors. Stay indoors for 30 minutes after the last thunderclap.

中文步骤

  1. 立即前往坚固建筑物（有管道和电线）或硬顶金属车辆。如果没有避难所，避免开阔地、山顶和孤立树木。只有在无法到达避难所且身处群体中时，蹲姿是最后手段，但不推荐作为主要策略。
  2. 遵循30-30规则：如果看到闪电和听到雷声的时间间隔小于30秒，立即进入室内。在最后一次雷声后，在室内停留30分钟。

Dead Ends

Common approaches that don't work:

  1. Crouch low with feet together to minimize height and step potential 85% fail

    Crouching does not significantly reduce risk; step potential is a minor factor compared to direct strike; the primary danger is being the tallest object, which crouching does not solve

  2. Lie flat on the ground to present a lower profile 90% fail

    Lying flat increases the area of contact with the ground, raising the risk of ground current injury; it also exposes more of the body to a direct strike