“…Summer. [Summer dissolves the humours and weakens the vitality (Rhazes).] Eat sparingly of foods. Moderate the drinks. Moderate the exercise. Take sufficient rest. Use diuretics plentifully. If emesis is possible, it is 'advisable. One should keep in the shade, under cover. The food should be infrigidant.”
http://data.nur.nu/Kutub/English/Avicenna_Canon-of-Medicine_text.pdf