i think it just proves frankyboy if your fitness is good then you can stand the heat a lot better than the average guy.
ive always been a serial abuser of my body with junk food,drugs and very large amounts of alcohol,smoking,no exercise etc.
ive cleaned my act up over the last 10 years or so.no drink,drugs or smoking anymore(although i "vape" e-cigs!).ive cut down on the junk food and im starting to do a bit of swimming again.
i cope better in the heat than i used to but i still end up having to finish early if the humidity is high.
i wish id never touched a cigarette or any alcohol or street drug as i would be a lot healthier i reckon with a few more brain cells!but i cant change the past so its a salvage operation to try and keep my health at a reasonable level.
frankyboy you have my upmost respect when i hear of your feats for charity.you must be one fit guy!!id struggle to even run half a mile down the road without being totally knackered!!
best wishes
dazmond