The UK Health Security Agency (UKHSA) has issued a heat-health alert across the UK after the beginning of its second heat wave.

The alert will be in place from Tuesday afternoon until Aug. 13 at 6:00 p.m. local time across all regions of England and some regions in Wales and Scotland.

“Temperatures will feel very warm again this week, particularly in southern and central parts of the country. We want everyone to enjoy the warm weather safely when it arrives but remember that heat can have a fast impact on health,” Dr. Agostinho Sousa of the UKHSA said.

“It’s important to ensure that people who are more vulnerable – elderly people who live alone and people with underlying health conditions – are prepared for coping during the hot weather. The most important advice is to ensure they stay hydrated, keep cool and take steps to prevent their homes from overheating,” she added.

With the country undergoing a period of dryness, the UKHSA has warned about the risks of wildfires and has urged people to take caution when traveling and to stay indoors if they encounter smoke or fire outside.

The agency also advised people to stay indoors between 11:00 a.m. and 3:00 p.m., when the sun’s ultraviolet rays are strongest and to walk in shade when traveling outside.

When indoors, people should close their windows and curtains in rooms facing the Sun, thus reducing the risk of houses overheating.

The UK is set to face its second heat wave in less than a month with temperatures set to rise above 30 degrees Celsius (86 degrees Fahrenheit) and one that will last longer than the heat wave experienced in July.

“Heatwave criteria look likely to be met for large areas of the UK later this week, with the hottest areas expected in central and southern England and Wales on Friday and Saturday. Temperatures could peak at 35⁰C, or even an isolated 36⁰C on Saturday,” Tony Wardle of the Met Office said.

“Elsewhere will see temperatures widely into the high 20s and low 30s C later this week as temperatures build day-on-day through the week due to an area of high pressure extending over much of the UK,” Wardle added.

The warning from the UKHSA this week follows a partial hosepipe ban introduced by water companies in southern England over fears of drought from the impending heat wave.

Under the Temporary Use Ban, hosepipes will be prohibited from watering gardens, cleaning cars, filling pools or ponds and clearing out patios.

The month of July broke the record for being the hottest month in the UK, with temperatures rising above 40C (104F), the hottest since records began in 1836.

During this month, the UK was hotter than 98% of all other countries in the world.