It's horrid isn't it!! I have drank about 1.5 litres of water today already, plus 500ml of lucozade which is an isotonic drink that doesn't dehydrate but I am so dry in the mouth. I know that I am dehyrdated, because my skin turgor isn't fantastic (the fun and knowledge that comes with doing a Bach Nursing degree lol). I did a bit of reading on dehydration, and it is actually very easy to become dehydrated and if your mouth is dry then that is a sure sign that you need more fluids. I have gone and bought some hydralyte iceblocks (electrolyte iceblocks) to help rehydrate. Going to have one at night and one in the morning, to ensure I have plenty of enzymes and salts etc.
Highly recommend these to anyone who is feeling the same as me!
xoxo