Approaching thunderstorms can be recognized by rising pile clouds, sultriness with rising wind, thunder and lightning. The distance of a thunderstorm can be roughly estimated: The seconds between lightning and thunder divided by three result in the distance in kilometers.
Example: If thunder follows a lightning bolt after ten seconds, the thunderstorm is approximately 3.3 kilometers away - the next lightning strike can occur in the immediate vicinity!
In general, as soon as thunder is heard, people who are outdoors should seek shelter. Only when 30 minutes have passed after the last thunder, one can assume that the danger of thunderstorms is over. In addition to thunderstorm fronts, there are also local thermal thunderstorms that occur in the afternoon, especially in summer, when there is little wind and high levels of solar radiation. With this type of thunderstorm, there is already a hazard with the first lightning.
Protected areas are e.g. in cars or in and around buildings with lightning protection systems. In general, metallic objects (bivouac boxes, etc.) act like a lightning protection system and can therefore offer a certain amount of protection against it. If necessary, further protective measures against flashover, contact and step voltages must be carried out in the protected areas. The right behavior of the people is also important here.
Carrying a radio in hand does not significantly increase the risk, not even when transmitting with it.
For permanent electrical installations, planning by a professional who knows the relevant electrotechnical standards and regulations is recommended.
Larger radio systems installed at times (with antennas in the treetops of exposed trees, etc.) should be able to be dismantled. When a thunderstorm approaches, the station should be able to be dismantled. The cables are unplugged and the antenna is terminated. Cables laid at a height are to be fetched (a rope pull facilitates the work). The more cables lead away from the radio station and the longer the cables are there, the more care must be taken. Not only from a direct lightning strike but also from an indirect one. Exposed metallic parts require a safe distance.
If the radio equipment is to work during a thunderstorm, you should seek advice in advance from a professional who is familiar with the relevant (electro) technical standards and regulations. Professional systems always provide lightning protection.
In tents you are not protected from lightning strikes, not even if you are sitting on a "sleeping mat". Likewise, caravans or mobile homes without a metal frame or outer skin do not offer any protection against lightning strikes.