It is no exaggeration to say Britain is in the grip of a skin cancer crisis, with cases reaching record levels.Melanoma – the deadliest form – is at an all-time high, with nearly 21,000 Britons diagnosed every year. And it's a trend showing no sign of slowing.With scorching summers set to become the norm in the UK, cancer specialists warn cases could climb to 26,500 a year by 2040. Meanwhile, there are around 200,000 non‑melanoma skin cancers treated each year – with numbers having more than doubled since the 1990s.The increase in skin cancer cases largely reflects the UK's growing and ageing population, Cancer Research UK – which carried out the analysis – said. But, according to the charity, the vast majority of these cases are preventable.The warning comes n the midst of a UK heatwave, with Met Office forecasters issuing a rare red weather warning for Wednesday and Thursday indicating 'a risk to life for even the healthy population.' So, with temperatures expected to reach sweltering highs this week – exceeding 39C in some parts of the country – how can you minimise your risk of the deadly disease? And what are the tell-tale signs and symptoms everybody needs to be aware of? Rates of one of melanoma skin cancer are at an all–time high in the UK, as Britain faces sweltering temperatures Watch out for white patches and disappearing molesMost melanomas are spotted because they appear as a new mole, or a change in an existing one – usually in areas exposed to the sun, says Dr Christopher Rowland Payne, consultant dermatologist at The London Clinic.But a mole that shrinks or even disappears can be a far less obvious – and often overlooked – warning sign.'Amelanotic melanomas may appear pink, or essentially clear and colourless, making them incredibly difficult to spot,' Dr Rowland Payne explains.This can delay diagnosis, with potentially life–threatening consequences. When caught early, melanoma is almost always curable – but it becomes far harder to treat over time.To help detect these more unusual cases, he advises checking your skin regularly for any subtle changes – including in moles you already have.'Dandruff' could a be a sign of something sinisterSkin cancer can develop anywhere on the body – but it is often hardest to detect on the head and scalp because it is out of sight.While many people remember to protect their face from harmful UV rays, the scalp remains one of the most overlooked – despite being highly vulnerable to sun damage.Persistent tenderness, redness around the hairline, or even what seems like stubborn dandruff should not be dismissed, experts warn – particularly if symptoms do not improve. Dandruff itself isn't a sign of skin cancer – but redness around the hairline and a flaky scalp can be 'It's not uncommon for people to burn along their parting, but many don't notice until it starts to peel,' Dr Rowland Payne explains.'By then, the damage is already done.'The problem is that this can easily be mistaken for a dry scalp or dandruff, when in reality the skin may be shedding as part of an inflammatory response triggered by sun damage.While dandruff itself is not a sign of skin cancer, a persistently flaky patch in one area can be.Key warning signs include large or uneven flakes, discolouration of the scalp, or bleeding.For this reason, it is worth spending a few extra minutes protecting these areas – applying sunscreen along your parting and wearing a hat, Dr Rowland Payne advises.Don't dismiss scabs on the scalp Dry, scaly patches of sun-damaged skin – known as solar keratoses – are not always cancerous, but they carry an increased risk of developing into skin cancer.