OK, let's say it's hot - ideally above 30C, but in any case above 22C. All you have to hand is ice cubes, water and instant coffee granules (and sugar, if you need it). Panic not, for a Greek frappe is yours for the making:

Get a shaker (in Greece every house has a plastic "cocktail" shaker for the purposes of frappe). Fill it half way with ice cubes. Add instant coffee granules and sugar to taste (and a little cold milk, if you really want it). Add water to just below the rim. Close shaker. Shake to kingdom come. Pour contents into tall glass. Insert straw. Sit on veranda/patio/balcony/rock and watch the world go by as you sip.

Good for any occasion, but ideal for having just come out of the sea, or for waking up after midday siesta.

Guess what - it's 23C today, and I just made one at the office. The colleagues think I am mad and are waiting for my head to explode. Aha! Give me time and I will have some more converts soon...