Bushwalking gear and paraphernalia. Electronic gadget topics (inc. GPS, PLB, chargers) belong in the 'Techno Babble' sub-forum.
TIP: The online Bushwalk Inventory System
can help bushwalkers with a variety of bushwalk planning tasks, including: Manage which items they take bushwalking so that they do not forget anything they might need, plan meals for their walks, and automatically compile food/fuel shopping lists (lists of consumables) required to make and cook the meals for each walk. It is particularly useful for planning for groups who share food or other items, but is also useful for individual walkers.
Mon 28 Jun, 2021 10:28 am
I've weighed myself before and after running in desert temperatures; around 35C and in two hours of training at a moderate pace I would loose between 3 and 5 kilos and spend the rest of the day rehydrating. I've seen resting metabolism rates reported as being as low as 100 watts and metabolic expenditure for some activities as high as 2000 to 3000 watts; for short periods.
Certainly when sled hauling I generate a lot of heat on the uphills
Mon 28 Jun, 2021 10:55 am
"Umm radiation works from a hot body to colder things.'
I don't think that this is the way it works. All bodies radiate (emission) irrespective of ambient temperature but heat absorption from radiation will be greater than loss if directly exposed to high radiation (i.e. the sun). A body will still radiate heat away even when exposed to direct sun: this is the property of radiant heat loss.
But, if bodies are in direct contact than heat will transfer from a hot body to a cooler body. This is the property of conductive heat loss.
In practice, we lose generated heat (and that gained by radiative absorption) mainly by evaporative heat loss.
IN hot weather we are best served by preventing heat production(slowing down work output) and doing whatever potentiates evaporative cooling - I agree that preventing radiant heat gain is an important point, though.
What is the role of clothing? I am not convinced either way - black garments radiate heat more quickly than white garments; so black clothes (if loose) have a theoretical advantage over white clothes in shedding gained heat (and a practical advantage if you ask a bedouin) but heat from solar gain will be greater as it reflects less.
I am no physicist but heat gain from air temperature should be effectively unaffected by garment colour (as it is about conduction) and so will evaporative heat loss.
So black loose clothes may be better but certainly less practical for bushwalking and if you wear form fitting clothes then white may be a better choice; but irrespective of this, promoting evaporative cooling and producing less body heat is essential. A parasol, if practical, is clearly the best option if absorption of radiant heat is a concern and loose clothing (promoting the chimney effect) is also good for promoting evaporative heat loss.
How well this works in practice has never been studied, I believe, since that 1992 paper about the Bedouin.
Personally, I haven't noticed a lot of difference in heat gain from the colour of my clothes but that is purely subjective. I tend to wear favour loose fitting clothes and avoid walking in the middle of the day either way.
Addit: in practice, my clothes are usually wet with sweat when I walk - water evaporates more quickly from a dark surface -is there a role in dark clothes if they are saturated?
My point being that there are more variables than just: white reflects more than black so therefore white is cooler.
Sun 15 Aug, 2021 7:38 pm
Colors for me are usually whatever is a year behind the trends.
As far as light vs dark, I've read in several places that it really isn't detectable to the wearer, all else being equal. So whatever. I do select at least some gear for visibility, but overall, I really don't much care. Perhaps my only concern is that in the current day and age, I do drift away from gear that is overly "paramilitary" thought I might roll some surplus gear, I tend towards stuff that is obviously vintage. If for no other reason than to not worry anyone I might come across, and as it has been an extension of much of my more recent purchases having been with "work" in mind.
Sun 15 Aug, 2021 8:57 pm
So many different perspectives I had never considered.
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