[arethuza]

Happens all the time in Scotland - I assume people look at the height of the mountains and assume they are safe for a quick stroll if the weather is nice.

e.g.

https://www.bbc.co.uk/news/uk-scotland-highlands-islands-457...

"Cairngorm Mountain Rescue Team said the walkers' attire had included shorts and leggings, but no jackets."

I've never actually said to people I've passed that I thought they were inappropriately dressed (though maybe I should do) - but I have given people maps and directions when they admitted they had no idea where they were or their phone batteries had died (I take backup printouts of maps so not a big deal to give a copy to someone).

[jschwartzi]

Yep that's a regular occurrence here as well. People assume that because it's in the high 70s on the valley floor that it will be the same temperature at the peak. Well, if you're gaining 3000 feet of altitude the temperature might be in the low 60s if you're lucky. And there will be wind chill as the air currents cut across the peak.

I've also seen a ton of hikers go 3 or 4 miles in without any food, water, or emergency gear at all.

I've heard of people on St. Helens doing the climb up the summer route in shorts and T-shirts with no other gear and becoming hypothermic at the top and requiring rescue. And that's a permitted route, meaning you have to win a permit lottery the year that you plan to do it.