Whoa, is it gettin' HOT here!

[Zone-5]

Oh I could do a schuss at Hut right now..

[wayno]

have their been any heat related deaths this summer? there were at least a couple in the media last year.

[Zone-5]

Centre court breakfast!

https://twitter.com/DjokerNole/status/4 ... 44/photo/1

[wayno]

Early figures indicate last week's heatwave may have been responsible for hundreds of deaths. The Victorian Institute of Forensic Medicine says it recorded double the usual amount of deaths last week.

click on Show Transcript

http://www.abc.net.au/news/2014-01-23/c ... ection=vic

[Zone-5]

Here we go AGAIN!

[Bubbalouie]

Here we go AGAIN!

Second round isn't as bad, you get used to it right.... 38C doesn't look particularly hot at all really (though I'd not go hiking in it). Even 40C seems manageable (just).

[Strider]

37.4C at my place right now

[wayno]

10 degrees this morning on my walk in the hills near auckland
do you know what the humidity is strider?

[Tex]

Adelaide is 37.4 ATM 8% hum.

[Zone-5]

10 degrees this morning on my walk in the hills near auckland
do you know what the humidity is strider?

Hobart: Relative Humidity = 42%

[Strider]

10 degrees this morning on my walk in the hills near auckland
do you know what the humidity is strider?

It was 28% earlier according to my weather station, but is up to 46% now.

[Zone-5]

Adelaide is 37.4 ATM 8% hum.

[wayno]

8% humidity the moisture gets sucked out of your skin...

[photohiker]

8% humidity the moisture gets sucked out of your skin...

Hate to break it to you wayno, the moisture in your skin is way higher than the air around you unless it is raining or you are swimming

It gets sucked out of your skin regardless of where you are. Even in NZ. Maybe it goes faster here though.

How about up in the alps, it's pretty dry up there too, isn't it?

[wayno]

friend of mine from did the john muir trail. low humidity there he complained of dry skin on the trail and needed to drink a lot to help offset water loss...
you do dehydrate through skin and respiration faster in low humidity than medium humidity
high humidity varies according to temp...

[Bubbalouie]

friend of mine from did the john muir trail. low humidity there he complained of dry skin on the trail and needed to drink a lot to help offset water loss...
you do dehydrate through skin and respiration faster in low humidity than medium humidity
high humidity varies according to temp...

The upshot is the the body's evaporative cooling works treat. If you can keep the fluids up you can "comfortably" do a day hike when it's 30-35C @ 10-20% RH, if it's 40+% RH it gets pretty yucky over 30C. This of course assumes you don't push yourself too hard and need to breath heavily a lot and is also very personal (some people cope with dry heat well, others will literally have the skin on their lips peel off in spite of drinking plenty).

I went for a stroll on Friday when it was about 28C but the RH was quite high (50% in town but much higher where I was) it was very nice close to town, the valley I was in was so humid that I had to turn back after just 3km, my nephew simply couldn't cope and I didn't want him keeling over.

In any case, my point is Adelaide's high temp (sub 40C days anyway) aren't too bad if the humidity is low which is usually the case.

[wayno]

its not just about evaporation, its about transpiration, you dont need to sweat to loose moisture, if you're in a low humidity environment, you simiply loose moisture to the air because of the difference in moisture between the two mediums and the airs ability to absorb extra moisture..
whether you like it or not in a low humidity environment your water loss increases by default. if you're sweating as well you're in for a whole lot of water loss, friend of mine works outdoors in inland victoria, sitting on a skidder, needs five litres of water a day at work, he's not exerting himself all day long, part of his water loss is the low humidity taking moisture through his skin as well as sweat... you dont loose that much water in nz in similar heat whre the humidity is higher....

[Bubbalouie]

its not just about evaporation, its about transpiration, you dont need to sweat to loose moisture, if you're in a low humidity environment, you simiply loose moisture to the air because of the difference in moisture between the two mediums and the airs ability to absorb extra moisture..

Agreed, the point is to drink plenty though (and keep up electrolytes).

When I was younger I did have days working as a labourer where going through 3 litres before lunch and another 4 in the afternoon wasn't out of the question.

I do however suspect individual physiology has an influence here (and perhaps what you're used to). When I exercise I sweat a lot if it's even just warm (think 20C). If it's very humid it's much harder for me to cool down. That may just be a personal quirk too though.

[wayno]

when its humid your sweat doesnt evaporate as much, so the cooling effect of sweating is less. the air has less capacity to absorb moisture, you may still sweat a great deal but the benefit is less than when humidity is lower and the sweat evaporates more readily. theres a reason why most animals are inactive in the heat of the day in hot climates...
humans are actually hard wired to sleep in the middle of the day, the reason you feel tired after lunch is only partially to do with the lunch you just ate... you're programmed to avoid being active the heat of the day and sleep it off. and then get active later in the afternoon when the temperature drops and the sun is less fierce. working nine to five is actually fighting against our own body clocks, even despite some humans living for thousands of years in cold climates their body clocks havent changed from when their ancestors lived in equatorial regions...

[Zone-5]

...you're programmed to avoid being active in the heat of the day and sleep it off.

I must admit, that has been my daily activity after much celebrations of late..

[photohiker]

I think I've got a broken program

At 2PM I was jacking up the car to swap a flat tyre, then I swept out the garage and moved the fire pump, pumped up the hand cart tyres because I had trouble moving the pump with it, then swept all the eucalyptus leaves from the path and put them in the compost bin. Then I took the wheel with the flat tyre and washed it so I can put it in the car and handle it without getting black.

Didn't feel hot until I stopped

[Zone-5]

Oh no, not again.. everyone here in Adelaide is just waiting for the next bush fire alert!
STAY TUNED

[Zone-5]

Must admit I was a bit faint out there on the tracks yesterday.

[photohiker]

43C predicted today in Radelaide but we'll need our warm coats tonight, it's dropping below 30C

http://www.abc.net.au/news/2014-02-02/a ... ed/5232956

Cut my walk down to an easy 2-3k per day this week. It was 32C on the trail this morning.

Also, check this cool Earth Wind Animation with Heat overlay

[wayno]

Dunedin 15 degrees at midday....

[Zone-5]

Got to 37°C here in SA yesterday! Why is it starting up again so soon?

I have heard it has got to do with the wandering jet stream here in the S. hemisphere...

[Strider]

36 today in Melbourne. And apparently we're going to be 10 degrees above average this summer!

[whitefang]

It was 30 degrees in Adelaide yesterday when I finished my walk at 10am... 21 degrees when I got up for another walk this morning. Lucky it didn't get above 30 today.

[Zone-5]

Grass fires are real danger here in SA. Definitely planning my next walk with this factor in mind.

[Tortoise]

Was still 30 degrees at 8pm tonight - NSW Central Coast