What was your temp? How did you measure? Headache may be related to effort, but fever would be a concern. How hot are the rides that cause the fever? How much are you drinking on these rides? If you really are getting fevers (ie confirmed w a thermometer) you should go see a doctor.

 

It almost got to 101 for a short time then stayed at 99 for a while. The fever always last less than 24 hours. The weather was 80 degrees. I had 2 bottles during the ride and another right after.

 

How's your hydration on these longer rides. I will get lightheaded/headachy if I don't hydrate properly on longer rides. Never paid attention to temps after but I wouldn't be surprised if I did have a mild fever to.

 

For 3 hours under 80 degrees 2 bottles is usually enough. Dehydration seems likely but I didn't have any symptoms of it. I was peeing clear and free of cramps. Hanging on for dear life to stay in group is the common denominator in getting these fever headaches.

 

I can only get away with 2 bottles for that time if its cool out i.e. 60's, hotter and I pay for it. Elevated body temp and headaches are both symptoms of dehydration. I would try carrying an extra bottle for your longer high intensity rides and see if that helps.

 

Hydration could explain some core body temp rise and a headache, but nearly 24 hrs of fever and headache well after exertion are kind of odd... I'm no doc, so fwiw, you might want to talk to your doc abut this. 99 might just be your measuring devise or technique, 101 not so much. Sunburn? Couldn't a good low level widespread burn wound do this?

 

Sunburn could make you hot, but I don't burn. I've gotten a bit dehydrated a few times. I got to the end of the ride with a very dry mouth, hard to swallow, and could only get out a scanty amount of yellow in the bathroom. I just drank a lot afterwards and I was fine.

Could it be an electrolyte thing due to exertion level? I think I'll try skratch labs or something on my next long hard ride.

 

Re-hydrating on water alone is not enough(I'm assuming your not using any electrolyte replacement now). Lots of good information out there on proper hydration, I like the info Allen Lim from skratch labs has put out there although I havent tried the skratch labs products.

 

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