Just look at those crisp blue waters (Picture: NEIL HALL/EPA-EFE/Shutterstock) If you’ve taken a glance at the weather forecast this week, one thing is clear: it’s about to get seriously hot. In London, today’s temperatures are set to reach 29°C; by tomorrow, it’s going to hit 36°C, while Wednesday could see highs as dramatic as 40°C. Brits will be flocking to outdoor pools to keep cool, but with tickets to popular lidos like London Fields and B…