In the summer months, temperatures can be very high. Many people enjoy this hot weather. There is plenty of sunshine and that puts people in a better mood. It also makes them want to go outside more. When we spend time in the sun, our bodies produce vitamin D. We also take more physical exercise, which can help prevent chronic disease.

The sun is constantly emitting energy. This is called radiation. Part of this radiation is visible to us. We see it as light. Another part consists of ultraviolet rays (UV radiation). These rays are invisible. UV rays are good for our health, but too much UV radiation is bad.