The wife of former Prime Minister Boris Johnson, Carrie Johnson, has issued a warning after she was rushed to hospital. The 37-year-old shared her message from her hospital bed on Instagram. The mum-of-four said she had been in hospital for two nights due to severe dehydration. On her Instagram story, she wrote: “Being hospitalised for two nights for severe dehydration was not on my postpartum bingo card”. She added: “Breastfeeding mums make sure you eat and drink enough in this heat. “Especially if your babe is cluster feeding”. In another post shared on her Instagram story, she thanked people for their messages and to the NHS. She wrote: “This week has honestly been brutal. Mastitis (me), reflux (her), dehydration (me). What a pair we are! “But thank you for all the kindest messages, especially all the brilliant advice on reflux. “Really appreciate it and made me feel way less alone going thru [sic.] it all. And as ever, thanks to our amazing NHS “. Last month, Carrie shared on social media that she and Boris had welcomed their daughter, Poppy, with a photo of the newborn with two of her siblings. Stay informed on the latest health news by signing up to our newsletter here . She expressed her amazement at how “pretty and tiny” Poppy was, and mentioned that her other children were “utterly delighted” by the new addition to the family. Carrie’s hospitalisation comes as temperatures have risen across the UK. In London, temperatures had risen to around 30掳C. The Met Office has warned that heatwave conditions could peak next week, which you can read more about here . The forecasting agency says that temperatures will generally rise through the weekend for those in the south, with in excess of 30掳C possible in places. NHS Wales says that symptoms of dehydration in adults and children include feeling thirsty, dark yellow and strong-smelling pee, peeing less often than usual, feeling dizzy or lightheaded, feeling tired, a dry mouth, lips and tongue, as well as sunken eyes. But signs of dehydration in a baby may include a sunken soft spot (fontanelle) on top of their head, sunken eyes, few or no tears when they cry, not having many wet nappies, and being drowsy or irritable. The NHS recommends that people should drink fluids if they have symptoms of dehydration. If an individual feels sick, or has been sick, and finds it hard to drink, to start with small sips and then gradually drink more. To keep your child hydrated, once dehydration has been treated, it’s important that the child’s fluid levels are maintained. NHS recommends that parents carry on breastfeeding their baby or using formula, and to try to give small amounts more often than usual. Alternatively, it recommends that parents give their baby small sips of extra water if they’re on formula or solid foods, to give regular small sips of rehydration solution to replace lost fluids, but it is recommended that parents ask their pharmacist to recommend one, and to give small children their usual diet.