Not recommended nowadays but Salt Tablets.

Many years ago and I was working in the sun- heat and Humidity in France. Used to travel to the area and at 1pm I was there and ready to start work. Except I couldn't It was a long time to unload the van and prepare for an afternoons driving and sorting on the track. Then one year I aquired salt tablets. Took one when I arrived at 1--By 2 the van was unloaded and were on the track sorting for the next day. I was finished by 4- back ayt the hotel by 6 and in for dinner by 7. The other teams could not start parctice till it cooled down at 6. Don't think they had dinner that night.

Salt is frowned upon but it does work. One of my mates sugffered Heat stroke that weekend and he had to lie under a tap to cool down. I got him to take a salt tablet and 30 minutes later he was fine.

Now on rides and if it is going to be humid I take Marmite sandwiches. Marmite has most of the essential salts in it and does aid at the point where you begin to suffer. If you take it before the suffering starts---you won't realise how close you were to it.,