I tried it - it came our very sour and strong at the same time
- cooked up some sliced fresh lemon in a pan with some water, mixed with honey and more water - urgh it left me feeling worse!
Does he have a favourite fruit juice? Orange, apple, cranberry, grape etc.?
You can put a teaspoon (level) of honey in a mug, add half a cup of boiling water and top up with as good a fruit juice as you can muster. Vitamins in the fruit, good properties of the honey, warm and comforting from the water which also makes it tasty but not too sweet or strong.
Failing that - lemsip powder, spoon of honey, make with hot water and top up with orange juice (in the same proportions as you would do water / milk for a cuppa but water / OJ instead).
Hope his plague passes soon
x