It's so hot lately that I often don't wear a watch at all but use my "G-Shock-pocketwatch" instead - the HS-80TW. I love the features. It has 12 (!) alarms, a countdown with repeat and stopwatch (obviously) and a soccer timer. A huge CR2032 gives it a battery life of 5 years (when using the stopwatch every day - the manual mentions 30 button presses a day). If it had illumination it would be perfect.
@Sedi We had record breaking 3 weeks constantly temperatures between 33-35 °C and sunshine. Torture but since Monday lots of rain and significantly cooler. It's a blessing