So, pretty much yes then.
Just a quick google tells me that 33 DegC wet bulb is equivalent to 44DegC at 50% humidity. London is 31 DegC and 52% humidity today. So another 13 degrees to go (without any change in ambient humidity).
So, yeah, i suspect it's never hit 33DegC *wet bulb temperature* in the UK. Not where you're likely to be exercising anyway.
Maybe on the Tube. But i don't know many people who go down there to exercise.
Well, pretty much no as well.
To get effective cooling you need an approach temperature. Google suggests that skin temperature during exercise is 27-29C, and your core temperature is ~37C.
So the heat generated has to transfer from that 37C core to the 28C skin, and then from the 28C skin to the air. You can't expect the body to effectively cool itself without the wet bulb temperature being significantly lower than skin temperature.
Industrially you would assume an approach temp of ~5C to be the minimum depending on the economics of the application. But if you reduce the approach temp, then the heat transfer reduces by the same factor, or the area required increases by the same. e.g. if I need to transfer 1kW with a 5C approach and a heat transfer coefficient of 100W/m2.K, then I need 2m2. If you reduce the approach to 4C then i would only be able to transfer 80W, or require 2.5m2 etc. Obviously the body can't change its size rapidly, it can adjust skin temperature via blood flow but you still need that temperature difference from the core to the skin otherwise your core temp would rise, but otherwise the only variable it can control is the amount of heat it needs to get rid of.
Biology seems to agree with engineers that about 5C is needed, The American College of Sports Medicine's recommends a wet bulb temp of 23C being the upper limit before college athletes should modify or postpone exercise. Wet Bulb Temperature and Exercise
you should see what the schools are doing <runs for cover>
Our local schools were closed for two days, quickly followed by a dispersal order for one of the beaches where kids like to jump off the rocks, etc. It's too dangerous to have them in school but they make too much mischief on the beaches where they are attempting to keep cool. Get them sitting in their nuclear reactor living rooms quietly revising until they evaporate, I say!
Our closest beach was rammed yesterday afternoon and the population seemed an odd shade of lobster red. I suspect that the increase in cardiac arrests may be more to do with this than the odd cyclist pottering around.
it's more 'what happens to evaporative cooling you factor in a lack of movement'... you just need "sufficient" to allow evaporation to do its thing.
My question was more rhetorical than anything. Anybody who rides on hot days knows the answer.
I've left the bike at home today and driven to work
This I really cannot get my head around. Why would anyone sit in a car in days like this when you have a bike and a natural cooling effect? I guess your aircon works in the car? I've never had a car which has not lost aircon gas after a few years (loads of places off "regassing"). That gas is way more of a greenhouse gas than Co2. Way more than 50% of cars I cycle past on my commute have their windows open and I bet the drivers are suffering the heat more than I am.
I'll have a lovely leisurely cycle and enjoy the natural free cooling.
This I really cannot get my head around. Why would anyone sit in a car in days like this when you have a bike and a natural cooling effect? I guess your aircon works in the car? I've never had a car which has not lost aircon gas after a few years (loads of places off "regassing"). That gas is way more of a greenhouse gas than Co2. Way more than 50% of cars I cycle past on my commute have their windows open and I bet the drivers are suffering the heat more than I am.
I'll have a lovely leisurely cycle and enjoy the natural free cooling.
For the ultimate smugness, motorbikes.
All off the breeze, none of the effort.
Apart from all the molten tarmac last nights ride home was remarkably pleasant in modern AA rated casual textile gear rather than the hot/unbreathable suits of old!
Just in from a walk, bike and horse ride in SW France. Quite warm, hot even, but low humidity. I've been riding up to about 37°C over the last few days but back home before the hottest of the day. It's the second heat wave of the Summer so I'm feeling acclimatised i.e. sweating a lot all over. So I'm pretty much with TJ, I'll simply add "listen to your body and head", if they tell you to drink - drink, slow down - slow down, find some shade - find some shade, give up - give up.
Science is your friend
https://link.springer.com/article/10.2165/00007256-200434010-00002
Among US high school athletes, heat illness is the third leading cause of death. Significant risk factors for heat illness include dehydration, hot and humid climate, obesity, low physical fitness, lack of acclimatisation, previous history of heat stroke, sleep deprivation, medications (especially diuretics or antidepressants), sweat gland dysfunction, and upper respiratory or gastrointestinal illness.
taking the guys in the OPs example
IF the guy is fit, used to exercise at hi temps, has no underlying health issues and makes sure their fluid intake keeps up then its probably fine , tho specifically for oldies they have to be extra careful as their ability to regulate temp decreases https://pmc.ncbi.nlm.nih.gov/articles/PMC6098859/
aging is associated with an attenuated physiological ability to dissipate heat and that the risk of heat-related illness in these individuals is elevated, particularly when performing physical activity in the heat
theres no way of escaping the fact that risk of heart attack or stroke is increased by hi temps, probably also worth bearing in mind that ambulance service is currently being impacted by heatwave worse than it does in winter! so if something bad does happen the wait is going to be longer https://www.bbc.co.uk/news/articles/cvgdw582wgwo
sadly we live in a world thats had enough of experts
Once again another misinterpretation of what I posted by @Duggan , not trying to impose anything on anyone just showing concern for people, ultimately it's a free country .
You literally said "Anything above 33° is excessive don't exercise " in your OP so my post clearly wasn't a misinterpretation, was it.
I am sure we all agree on the fundamental underlying point though- people should use a huge amount of caution when exercising in any extreme weather. I just don't agree with the arbitrary 33 degrees blanket rule, sorry.
Come off it kimbers, that comment about experts was uncalled for.
We have all been riding in this weather, it is personal judgement and sometimes people get it wrong. It doesn't support a blanket prohibition though
If it doesn't I can only charge the car between about 0300 and 0900 when it's cool enough.I guess your aircon works in the car?
Thread summary
OP questions whether it’s sensible to do an 80 mile road ride when it’s very hot (it can’t actually 39 unless we are outside the the uk), if your 80 years old.
Lots of replies saying it’s ok but making no reference to age.
Age seems to be a massive factor in heat stroke
https://www.otsuka.co.jp/en/health-and-illness/heat-disorders/age/
No, he says his mate is 80, then blankets no exercise to whatever age.
But if we say that's implied to age, then again it's about using your own personal judgement. No one is denying that there is an increased risk of exercising in heat. What is being questioned is the blanket judgement. 80 miles on a bike could be done at a very steady pace, or it could be full on chain gang style. An 80 year old could be fitter and healthier than a 50 year old.
I know I'm a lot hotter here sat behind a computer than I am riding my bike.
This what he said. I can’t find anything that suggests exercising at a wet bulb temperature of 33 degrees centigrade isn’t s serious risk. The UCI classifies 28 degrees centigrade as its heightest risk level. The uk isn’t at that level at the moment
https://www.cyclingweekly.com/racing/what-is-the-ucis-extreme-weather-protocol
Just read advice from a cycling coach and a thing called wet bulb temperature which is particularly relevant this heatwave with such high humidity.
Anything above 33° is excessive don't excercise
Work closed early today because of the heat, I was planning on riding after work anyway so I just went at 1 instead, absolutely boiling! It was horrible in the open bits but so nice in the woods with a breeze. Currently rehydrating with a cold beer. Can't imagine riding road or anywhere too exposed in this heat.
There's an awful lot of twaddle and alarmist crap being spouted.
Yes it is hot. Yes it is almost (like 99.999999 %) definitely a result of global warming and yes that is not a good thing. However not all of us find the heat an issue. A few years ago in Crete I went for a long run in 44 degrees. It was so invigorating. Road riding in the mid 30's is lovely. Not for everyone of course but I do wish people would separate the climatic issue and the fact that temperature preferences are individual. I also love winters when it drops way below zero. Minus 18 a good few years ago in Betws y Coed was great and on Snowdon it was even better. I would admit to preferring a 30 degree drop i9in night time temperatures if only that was possible! hmmm
Just tried to play it a bit sensibly the last couple of days.... a gravelish/towpath/road yesterday... kept it under 1.5 hours and could get a reasonable amount of shade... a 1.5 bottle ride (on e-gravel bike)
Today nearly all gravel out a Swinley, not a lot of shade other than Crowthorne woods area. Again, kept it under 1.5 hours... 2 bottles and again the e-gravel bike.
Both rides started before 09:00, Took it at a comfortable pace and as a 79er survived it without any discomfort.
The UCI classifies 28 degrees centigrade as its heightest risk level. The uk isn’t at that level at the moment
It was on Wednesday and Thursday, they put the UCI Extreme Weather Protocol in place for the British Cycling National TT Championships. It allowed feed zones and stipulated the provision of shelters at start / finish.
It was absolutely sweltering. 34°C air temperature but on the road was up in the 40s.
Thankfully it's much cooler now for the Circuit Championships and Sunday for the road race looks like being back at normal summer temperatures.
I went out for a ride this morning and it was still high 20's, a couple of the climbs were really quite sweaty. 🥵
The thing is UK residents are not 'Conditioned' or acclimatised the average temp for the last month has been what? ~18-23 degrees in the space of two days it rocketed up by ~10-15 degrees. Nobody was physcally ready for that especially older people.
Yeah, I was going to talk about heat acclimatisation. Ironically I've been doing some indoor stuff with temps inside mid to high 20s, and it's actually stood me in quite good stead for riding outside in similar / slightly warmer temps in the last few days.
Shady, flattish trails on the gravel bike have been fine. I wouldn't have wanted to be banging out big, hilly rides, just unpleasant. I always think with stuff like this, the real problem is when people have no appreciation of the risk they're taking rather than people making an informed decision.
The pup on the other hand, mostly black coat and 34 kilo of solid muscle does really badly in hot weather and while humans get the bulk of their heat acclimatisation in around ten days, dogs can take up to 60 and still don't do as well. We've been doing 5am walks, which is oddly zen, but not great for my ongoing grump levels. Time for bed said Zebedee.
Thank god the likes of oldfart weren't in the desert rats when they were facing down Rommel.
The desert rats were acclimatised troops in their 20s fighting a war. They risked their lives in pursuit of the reward of national survival.
In contrast oldfart highlighted 80 year old cyclists risking their lives for the reward of a bike ride they could have cut shorter or done next week when the temps will be 15c cooler.
Best start to a summer in ages let him enjoy it he's not doing a lot wrong if he's 80 and still at it .honestly common sense needed and crack on .....why is the modern world so dramatic about everything
and he could be run over next week or have something else finish him off .let him live his life he's 80 not done a lot wrong in getting there by the sound of it .Thank god the likes of oldfart weren't in the desert rats when they were facing down Rommel.
The desert rats were acclimatised troops in their 20s fighting a war. They risked their lives in pursuit of the reward of national survival.
In contrast oldfart highlighted 80 year old cyclists risking their lives for the reward of a bike ride they could have cut shorter or done next week when the temps will be 15c cooler.
Absolute snowflakes
With all the talk of temperature and scientifically-proven thresholds etc...
it's also worth bearing in mind that direct sun has a large effect and being out on a sun-baked road with no shade is a hell of a lot worse than being under a tree on grassland. The nominal air temperature from a well-sited weather station is only half of the story.
Had a lovely gentle ride a couple of days ago to a pub for lunch (under a tree in the beer garden). Tarmac melting on the way home. Yes it was hot but not unbearably so up in grim Yorkshire. Not the day for an epic ride though.
Anything above 33° is excessive don't excercise
Im gonna disagree with that. I have cycled weeks on end with temps above that. I have worked outdoors with temps above that. I have climbed mountains in temps above that. Just keep hydrated and don't push too hard
Yep but you’ve acclimatised and are sensible enough to hydrate and not push hard,you can’t assume people are applying the same un-common sense.
Rushing out the door at 80 in 40c to do a 60 miler unclimatised seems a tad rash when you can do it next week in high 20s.
(it’s different riding in a chain gang on the road thou as your speed is high so you exposure is less and you’ll probably set off in a much lower temp in the morning and the temp will be rising so your not actually riding in 40 until the end )
I used to cycle solo in hot weather 35+ but tbh it ends up a hot pootle and hydration competition as opposed to fun.
And if people well used to it are calling it a day…..
The thing is UK residents are not 'Conditioned' or acclimatised the average temp for the last month has been what? ~18-23 degrees in the space of two days it rocketed up by ~10-15 degrees. Nobody was physcally ready for that especially older people.
Yeah, I was going to talk about heat acclimatisation. Ironically I've been doing some indoor stuff with temps inside mid to high 20s, and it's actually stood me in quite good stead for riding outside in similar / slightly warmer temps in the last few days.
Shady, flattish trails on the gravel bike have been fine. I wouldn't have wanted to be banging out big, hilly rides, just unpleasant. I always think with stuff like this, the real problem is when people have no appreciation of the risk they're taking rather than people making an informed decision.
The pup on the other hand, mostly black coat and 34 kilo of solid muscle does really badly in hot weather and while humans get the bulk of their heat acclimatisation in around ten days, dogs can take up to 60 and still don't do as well. We've been doing 5am walks, which is oddly zen, but not great for my ongoing grump levels. Time for bed said Zebedee.
I find my dogs want to get up at 4 and 6 in the morning 🙁
Yep , big difference in being aware of dehydration,heat stroke and prepping against it on choice of route and amount of shade and adjusting accordingly.
‘Mad dogs and Englishmen’ as they say around here.
I think the issue is that U.K. climate isn’t that hot normally and people are unaware of the danger as it’s a thing they don’t normally encounter.
If you’re your a snow flake this weather really would be the end.
i for one absolutely hate the super hot weather that we have had this week.
i was lucky to get a new specialized epic comp ht on friday and rode it back 10 miles (i had been suffering with the heat up to then from the previous 2 days of 35c plus temps and lack of sleep,this is all just from being at home).
it was horrible (fair play to the people who can ride in those temps) and was glad to get home in the end as i was sweating and feeling like i was in an oven.
i cannot wait to start riding my new bike but at comfortable temps 😉
and he could be run over next week or have something else finish him off
While this is true as far as it goes for every single person walking the earth it fails to acknowledge the false equivalence about levels of risk.
Being a freak statistic from a car crash, bus crushing or sudden unexpected medical event is quite different to making a conscious decision to do something that's not necessary but that puts you at significantly elevated risk of a serious medical emergency or death.
- Dinghy sailing in 25mph winds is risky
- Dinghy sailing in 50mph winds and huge waves is inviting the Grim Reaper in and offering him tea and cake (at least for many club level sailors)
I don't know what the right answer is for the 80 year old in the OP's post (that's ultimately up to them to decide) but if we're discussing the principles of when is too much and what affects that then we should at least do it with a proper measure of relative risk.
I have been touring in the USA getting 35C temps early in the tour before I was fully fit. The humid east coast as well. That was about my limit. Ride early, plenty fluids, don't push hard. I am also carrying a fair amount of insulating blubber.
As others have said though there is always a breeze when cycling. I see no reason a skinny fit guy can't ride in current UK temps.
Ebike for me in this heat and even so was sweating profusely today. Garmin "estimated" 4.3 litres of sweat loss.
The main thing I do, apart from taking on fluids is monitor my HR as I know I have some issues. On an ebike it's much easier to regulate, but I was putting a fair bit of effort in to conserve the battery. I perspired much more today in the mid/high 20's temperature than I did yesterday in the low/mid 30's
I reckon I took in around 3l of water during today's ride - we did have 3 pints of lager en route though 😂
Both my (considerably fitter) mate and I were pretty goosed after 33 miles/4200ft
I did 80k today, gravel and tarmac. Brought loads of water, gels and jellybeans. It was bloody hard. But wanted to get out. Went out at 3 back at 8. So slow. But deliberately so. Strava tells me it was 30 degrees most of the ride. Feel ok but In retrospect might have been easier when younger.
When we did the King Alfred Way it was over 30 for 2 days. On the first day i didn’t drink enough, although i did lie in a chalk stream for a bit. Day 2 i drank 6.5 litres whilst on the ride
I rode yesterday.
Shimano winter boots as they are on their last legs and I save the good shoes for racing. Knee length tights with padded bib shorts underneath. Short sleeve jersey with a long sleeve base layer over top, sleeves mostly rolled up. Mid-thickness gloves.
My two friends both had shorts and short sleeves, summer shoes, one had no gloves and one had fingerless. They were complaining about the heat, I was fine.
65 miles of rolling back roads, and a swim stop at two thirds distance. I drank three bottles of water.
Some people just like it nice and warm, the OP's friend is probably like me. I bet he's waited months for the chance to get a warm ride, suffering through the British winter, desperate for a bit of sun, finally gets the temperature he likes and everyone else who prefer the cold tells him not to ride🙄
I would suggest a frozen sausage/lawn-interface but it's too hot and they'll melt before you're able to hammer them in.
What is needed is a frozen sausage setting tool.Which is something i've often mused about.
Similar concept to a crossbow, but instead of the arms and string, a straight spring similar to an air rifle.
Pull spring back, place frozen banger at the end and trigger release spring tension-driving sausage into the ground.
Quick,easy,efficient.
Durham City and return for me.Started at 5.30am.No need really as the hottest it got was 21C.Thank god.
For the ultimate smugness, motorbikes.
All off the breeze, none of the effort.
Apart from all the molten tarmac last nights ride home was remarkably pleasant in modern AA rated casual textile gear rather than the hot/unbreathable suits of old!
Clearly not riding in London at mostly 20mph, but with other options being car with broken Aircon or tube there really wasn't any contest despite nearly drowning in my own sweat 🥵
Smugness reserved for being 1hr quicker than car, zero congestion charge & parking charge 😉
People local to me have died dirt biking due to heatstroke. I’ve personally given hydration salts to two riders. Not the one in this link sadly:
https://www.nine.com.au/australia-news/qld/queensland-man-dies-of-heatstroke-20170116-p5v518.html
2 leisurely commutes and an evening group MTB last week. Garmin reading 33-34 degrees for all 3.
Luckily better than the forecasted 39-40. No humidity reading, but felt quite dry.
Stopping at junctions you really felt the heat off the tarmac and on your back - not sure it would have been as nice in the middle of a city. Air cooled while moving was actually quite pleasant.
Adapting your pace to the conditions. Admittedly harder to do if you are being controlled by a group.
This from someone who genearlly hates gyms and indoor sports because I get too hot.
Our group did our periodic night road ride from Cambs to Kings Cross on Saturday night/Sunday morning. It was a pleasure. I managed to clock 120 miles in low to high 20°C, a nice SW breeze and mostly in the dark. I drank 4L and held my nose for 3 McVomit stops as they were the only ones open. The deserts and coffee (with additional espresso depth charges) did the trick. Not very conducive to family or work time though so mebbies a bit of an exception. No 80 year olds died tho...
For the ultimate smugness, motorbikes.
All off the breeze, none of the effort.
Apart from all the molten tarmac last nights ride home was remarkably pleasant in modern AA rated casual textile gear rather than the hot/unbreathable suits of old!
Clearly not riding in London at mostly 20mph, but with other options being car with broken Aircon or tube there really wasn't any contest despite nearly drowning in my own sweat 🥵
Smugness reserved for being 1hr quicker than car, zero congestion charge & parking charge 😉
TBH I took my quad back for its second test ITV (Spanish MOT) last Thursday , my mono layer jeans weren’t bad but the textile was ok but yah not too bad whilst in flight but still a bit meh 😑
They chuck bottles of water at you,as it always scorchio,I love trundling around on the quad but I’m going to see if the mobile ITV gang will do it in 2 years time 🙂
Our group did our periodic night road ride from Cambs to Kings Cross on Saturday night/Sunday morning. It was a pleasure. I managed to clock 120 miles in low to high 20°C, a nice SW breeze and mostly in the dark. I drank 4L and held my nose for 3 McVomit stops as they were the only ones open. The deserts and coffee (with additional espresso depth charges) did the trick. Not very conducive to family or work time though so mebbies a bit of an exception. No 80 year olds died tho...
TBH Vampire Ride in the night, I’d be more worried about the missing locals 🙂
Our club is arguably overcautious when it comes to cancelling rides due to weather warnings, after 4 riders were hospitalised by ice one day.
Last week we took the view that there were no official club events while the amber alerts were in place. Plenty of folk went out and did their own thing, which is fine, their choice, they took precautions and no one died.
The warnings are partly in place to reduce pressure on the stretched NHS, and as a club, we feel we have to respect that. As a ride leader, I know at least two club members who fit into the "vulnerable" category who I really wouldn't want to be responsible for as I don't think I'd trust them to take it steady. Suspect there are more I don't know about!
Other local clubs were cancelling TTs etc
Anybody who rides on hot days knows the answer.Don't get to the bottom of a long sheltered climb when you're already pressing on and making the most of the cooling breeze. 10 minutes in you'll feel like you've just got out of the shower, with a heart rate of 180...
I rode the highest road climb in the country last week and took five minutes off my fastest time. I'm 59, you know....
Fair play to the 80 year old mentioned in the original post. Kark it on a bike ride after a full and active life - or in a care home with a bedpan wedged between your scrawny arse cheeks as you watch Homes Under the Hammer? Yes please!
