There’s a reason Ella Fitzgerald sang about how easy the living was in summer time. It’s good for us. The hot weather and longer days can have a huge impact on your health and wellbeing. Ever wondered why you come back from that holiday in the sun feeling invincible?

Here are five illnesses that can be helped by hot weather…

Cold and flu

We’re all familiar with that highly contagious flu virus. But luckily, the summer months help keep it in check. The word ‘influenza’ is said to come from the Italian phrase influenza di freddo, meaning ‘the influence of the cold’.

[Read more: Heatwave: How to survive the hot British weather]

In winter, we’re more likely to be crammed indoors, away from frosty weather, and so the scene is set for the cold virus to spread more easily and resign us to a few days of runny-nosed misery.

That doesn’t mean your risk of a cold in summer is nil. The pesky virus can come calling at any time of the year. Washing your hands regularly is one of the best ways to help keep a cold at bay.

Muscle soreness

There’s a reason personal trainers recommend saunas to their clients after that tough gym session. And why the posher of health clubs have saunas and steam rooms as standard. Heat helps.

Workouts cause miniscule muscle tears which leads to soreness. Hot weather can relieve soreness, as endorphins flood the body.

The heat also increases blood flow to our muscles and some believe this may also help your muscles feel less achy. Don’t stay in the heat for too long though and remember to stay hydrated. In a sauna, you’ll lose a pint of sweat in about 15 minutes!

[Read more: 6 everyday activities that are giving you joint pain - and how to ease the aches]

Sufferers of Polymyalgia Rheumatica (PMR), an inflammatory condition that can cause severe muscle pain, have said their symptoms have reduced in severity and, in some cases, disappeared altogether, when they have moved to warmer climes.

Arthritis

Icy wind can often exacerbate pain for sufferers of arthritis. There’s evidence to suggest that warmer and drier climates can reduce pain symptoms associated with the condition. Warm weather has also been linked to greater pain thresholds, as happy moods brought on by sunshine give us a greater ability to deal with the pain.

Vitamin D intake from the sun is also reported to help conditions such as rheumatoid arthritis and osteoporosis, a condition that makes bones fragile and prone to breaking.

Depression and vitamin D deficiencies

Getting out in that sunshine is just what the doctor ordered. In some cases, quite literally.

Vitamin D is produced by the skin when it is exposed to the sun. Just basking in a midday sun for 15 minutes of your day can be enough to provide you with a liberal dose of a vitamin which helps keep bones strong, keep lungs healthy and even help support the immune and nervous systems to run smoothly.

Vitamin D can also help reduce the risk of premature birth by half and helps regulate cholesterol.

[Read more: 8 scary signs you are not getting enough vitamin D]

Seasonal affective disorder (SAD)

Seasonal affective disorder is felt by many when the days get shorter and darker. Symptoms include low moods, lethargy and increased desire for carbohydrate-heavy foods, which can lead to weight gain.

SAD, although not fully understood, is said to be linked to lack of sunlight exposure, causing the body to produce melatonin, which makes you sleepy, and serotonin, which affects your mood. The hot, summer months can offer respite from this and improve your mood and feeling of well-being exponentially.

Do you suffer from a condition that improves in warm weather?