If it feels like this summer has been one long heat alert, you’re not imagining it. The UK has just recorded its highest-ever number of 34°C-plus days in a single year, the UKHSA has escalated heat-health alerts to amber across London, the East Midlands, the East of England and the South East, and Thames Water has introduced a temporary hosepipe ban. For a country built around mild, changeable weather, 2026 has been relentless.
Amber alerts aren’t issued lightly. They signal a real rise in health and social care demand — more pressure on GPs and NHS 111, more risk to older people and anyone with an existing health condition, and a level of heat stress that catches even fit, healthy people off guard. Training, commuting, or just getting through a working day in that kind of heat puts a different kind of load on your body than most of us are used to planning for.
Sweat is more than water loss
When you sweat heavily — through exercise, a hot commute, or simply a warm office with no air con — you’re not just losing fluid. You’re losing sodium, potassium and magnesium: the electrolytes your body relies on for muscle function, nerve signalling and maintaining fluid balance. Replace only the water and you can still end up under-hydrated in the ways that actually matter, which is why plain water alone often isn’t enough during extended heat.
What this means for your routine right now
• Don’t wait until you’re thirsty — thirst is a lagging indicator, especially in humid heat where sweat doesn’t evaporate as efficiently and your body struggles to cool itself
• Front-load hydration before you know you’ll be exposed to heat — a commute, a training session, a day outdoors
• Replace electrolytes, not just fluid, particularly after any extended sweating
• Keep an eye on UKHSA alerts for your region — amber means it’s time to actively adjust, not just tolerate
This is exactly the gap our Slip & Flow Electrolytes are built for — a clean, Informed Sport-certified way to replace what heavy sweating actually takes out of you, without unnecessary fillers or sugar loads. In a summer where the alerts keep coming, treating hydration as an afterthought isn’t really an option anymore.
Stay cool out there.
