We spend so much of the year wishing it was hotter but then when the mercury rises we can be unprepared for how it will change our training. A few years ago I managed to give myself heat exhaustion while playing tennis so I would urge you to listen to your body. On the day in question it was very hot and I was playing singles in a dome which felt a bit like a greenhouse. I drank some water but felt myself getting more and more fatigued as the sets went on. I started getting a headache and my vision went a bit funny. By the time I got home afterwards I was really confused and felt sick. It took a while to feel normal again. Ever since then I make sure I drink a sports drink (contaning glucose and sodium to keep the levels in my body balanced) if exercising intensely/for long periods on a really hot day. I also take regular breaks and seek shade to cool down. If running then I will try to avoid the hottest time of day and cut distance if necessary. There is no shame in changing how you train to fit the weather conditions and heat exhaustion feels absolutely horrible so do all you can to avoid it! Also make sure you slather suncream all over exposed skin even on cloudy days as often the clouds clear in the middle of a run. A baseball cap, shorts and loose fabrics that wick moisture from the skin can help keep us cool on a hot day too. An anti chafing gel applied to areas you know tend to rub together helps avoid pain later in the shower too. Remember to drink enough fluids before and after exercise and stay safe out there!