There are many telltale signs that you might be dehydrated. These include: a flushed face, extreme thirst, dry, warm skin, cannot pass urine or reduced amounts that can be dark and yellow, dizziness made worse when you stand up suddenly, weakness, cramping in the arms and legs, sleepy or irritable, feeling unwell, headaches, dry mouth, dry tongue; with thick saliva. One thing you can do is open your mouth wide and look at it in a mirror in a well-lit room. Well-hydrated mucus membranes should appear moist, shiny and without any cracks or discoloration. Dry mucus membranes are dull and may be ‘brittle’ in appearance. Another thing you can do is pinch your excess skin and if it bounces right back, you are hydrated but if it stays pinched, then you are dehydrated.