真的比周圍熱的那一塊
這一族是畫面最字面的樣子：那塊亮起來的地方，溫度（或輻射）真的比旁邊高。從一碗湯，到一座火場，到一整顆星球，尺度變了，畫面沒變。
noun · B1
A small area that is much hotter than the area around it, or that has much more radiation than the area around it.
高溫點
核心畫面
Picture a thermal camera picture of a wall, a bowl of soup, or a whole country. Almost all of it is a cool, even colour. Then one small patch glows. Nothing else has changed — only that patch is carrying more of something than the space around it. Every use of hot spot can be read off that picture: pick the patch, then decide what the 'heat' is. Sometimes it really is heat. Sometimes it is people, or trouble, or a signal, or a screen that answers you back.
可以想成一張熱感應照片：整面牆、整碗湯、整張地圖，大部分是一片冷色，只有一小塊亮起來。hot 是「多」，spot 是…更多收起
可以想成一張熱感應照片：整面牆、整碗湯、整張地圖，大部分是一片冷色，只有一小塊亮起來。hot 是「多」，spot 是「一小塊地方」，合起來就是「這一點特別多」。後面所有用法，都是換掉「多的是什麼」而已：有時候多的是溫度，有時候是人潮，有時候是麻煩，有時候是訊號。From the word’s history
Wiktionary records the compound as simply hot + spot.
來源只說這個字是 hot（熱）加 spot（一小塊地方）組成的複合詞；其他各種意思之間的連結，是理解上的比喻，不代表歷史上的先後。
Wiktionary (kaikki extract, packet source_ref kaikki:3f6f69a190036ae4:1142339050:33029): "From hot + spot."
Four branches
人氣集中的那一點
熱從溫度換成人潮：整條街上，只有那一家「熱」得起來。
noun · B2
A place that a lot of people go to for fun — a club, a music venue, a restaurant — because it is lively and popular at the moment.
熱門去處
麻煩集中的那一點
同樣是地圖上亮起來的一點，但這次亮的是壞消息：問題在這裡比別處嚴重得多。
noun · B2
A place where trouble is likely or where one particular problem is much worse than in other places — for example a place with fighting or political unrest, or a place with the worst pollution, disease, or accidents.
問題熱區
畫面上、訊號上「活」的那一點
熱在這裡變成「會回應、有訊號」：一整片是死的，只有那一小塊接得上、點得動。
noun · B1
A place, such as a café, an airport, or a library, that has equipment sending out a wireless signal, so people there can connect a phone or a computer to the Internet without a cable.
無線上網熱點