What should you know about hot weather nausea?

Heat makes the body send more blood towards the skin and increases sweating. Losing fluid and salts can leave you weak, dizzy, headachy or sick. Nausea may appear with heat exhaustion, especially after exercise, outdoor work or time in a poorly ventilated place. It can also happen because heat changes eating and drinking habits, or because food has been stored unsafely. Vomiting, diarrhoea, abdominal pain or fever point towards a gastrointestinal illness such as Food Poisoning or Gastroenteritis rather than heat alone. Reflux, Gastritis, Gallstones, Hepatitis A and low blood sugar are other possible explanations, each with different features.

Move to a cool, shaded or air-conditioned area and loosen excess clothing. Rest, sip cool water or an oral rehydration drink, and avoid gulping a large volume if that worsens the nausea. Once settled, try small amounts of plain food. Avoid alcohol and strenuous activity until you feel normal. If symptoms began after a new medicine, do not stop a prescribed treatment without advice; ask a pharmacist or clinician whether nausea or heat sensitivity could be relevant. Keep a note of when symptoms started, what you had eaten and how much you had been sweating.

Seek urgent medical help for confusion, fainting, a seizure, very hot skin, severe weakness, chest pain, trouble breathing, blood in vomit or inability to keep fluids down. These can signal serious overheating or another emergency. Arrange prompt assessment if nausea persists after cooling and drinking, returns repeatedly in hot conditions, or comes with severe abdominal pain, yellowing of the skin, fever or very little urine. Children, older adults, pregnant people and anyone with a long-term illness may become unwell sooner.

Could my symptoms fit heat exhaustion, a stomach illness or a medicine effect? Which fluids are suitable for me? Do I need an examination or tests if this happens again?