Sounds almost exactly how I felt, glad you’re ok. Really wrecked me for several days, was short of breath all last week. Scared the crap out of me.

The day started warming up very quickly, hitting about 85F and humid before long. I carry a Nathan waist pack with two 22oz water bottles, which is usually fine, though I plan runs to be able to top off my water as needed. Because my route followed a bike trail along the river, there was very little shade, and I was sweating profusely.

About six miles in, there’s a park with a water fountain, and I took the opportunity to splash my face with cold water and top off my water bottles. I had probably consumed about 20oz at that point, but there’s no harm in keeping the bottles full. I would usually have another opportunity to top off my bottles at around mile 9, but the fountain was not on in that park. At that point, I had plenty of water, but was very hot along the exposed beach.

After leaving the beach, I ran through some mild to moderate hills, and at about mile 12, I hit the wall like I never have before. My legs got heavy, and I started getting dizzy and sucking huge lungfuls of air. At one point, I looked down and my skin was very flushed and red. Even the palms of my hands were flaming red. I stopped and sat down in the shade of a building for several minutes until I could cool down slightly. It was scary.

Over the last six miles or so, I stopped in the shade at least six times. I was almost out of water, so I was wringing sweat from my hat to help cool down my face and neck. I could maintain my pace while I was moving, but whenever the heat caught up with me, I got weak and dizzy and out of breath.

As soon as my run was over, I drank a large bottle of water and a large iced coffee, totaling probably 50oz. This is on top of the approximately 60oz I drank while running. Drinking all those fluids at once at the end of the run was probably a mistake. I ate a small meal, took a cool shower, and then went grocery shopping with my wife. At the store, I got dizzy, very nauseous, and kind of short of breath. I chalk that up to hyponatremia, and it stopped after I had a fastfood burger and a couple of salt packets.

For my body to have such an extreme response to what should not have been an extreme workout was scary. I’m going to pay more attention to the temperature in the future and start long runs earlier in the morning. I’m also going to pay more attention to salt intake when drinking a lot on a run.

Why not try two short hikes/walks/runs rather than just one longer one. Give you body a chance to cool down in between and provide a nice double stimulus without any single bout of exercise being too stressful.

Opted for a hike today instead of a run since it was still pretty hot. Felt fine on the hike, but afterward a bit short of breath. Think I may need a day off tomorrow.

I wonder if the bodies shock at finding unexpectedly hot conditions had a lot to do with your reaction as the conditions themselves.

Could you central governor being upset by the your expectations of cooler conditions and prior runs in cooler conditions, compared the conditions that you encountered where your core body temperature rose quicker than expected?

It’ll be interesting to see how you cope next time you got out in similar conditions, I suspect both physical and neurological adaptations will have started to take effect and you’ll have a much more mild reaction.

Last summer I had a two week holiday in Spain and by the end of the holiday was able to do a tempo run in 35 degrees Celsius without undue stress. I never realised just how much I was sweating until I got indoors and out of the wind – suddenly I was drenched in sweat. It was really impressive to see how well I had adapted to the conditions. It took around 10 days to get really comfortable running in the hottest part of the day.

Though it’s early June, the humidity in Georgia, like other states in the Deep South, can be devastating if you aren’t acclimated. On the sixth loop, I felt like I was close to falling over from heat exhaustion, and it took me hours later in the day before I finally peed again. Heat, coupled with humidity, can wreck your run quickly. Run wisely.

Sure, you have to run in heat to acclimate which is why I do it, but pushing too hard in heat when not acclimated is not wise. There’s a difference between a hard workout and a hard workout in environmental conditions that could make it downright dangerous. My wife and kids wouldn’t appreciate a call from the hospital because I ran myself into heat stroke.

I live in the Northeast US, very cold, snowy winters, hot summers but only for a few months. I ran a lot of runs in -10 Celsius or below this winter, and 88 converts to about 31 Celsius. The change is pretty rapid during May and June, and lack of acclimation causes me problems a few times each Spring when I forget that my body is not yet prepared to run in heat.

I need to read that book, but it’s a daunting one. I’ve spent the past 3 months working through the Game of Thrones books, now finished, so maybe onto some non-fiction :)

*Noakes has lots on what defines dehydration and heat exhaustion.

By the way, being from Aus I’m not sure how hot 81 in fahrenheit is or what it usually is over in the us of a.