Warning not to travel as heat severely disrupts Sussex trains
Thameslink, Southern and Gatwick Express services are all affected
There's warnings not to travel as extreme heat disrupts train services across Sussex.
It's as part of the county sees a weather warning upgrade to red - the most severe of it's kind.
Speeds are being restricted and services cut on Thameslink and Southern services.
There'll also be no Gatwick Express services from the early afternoon.
Jenny Saunders, Customer Service Director at Gatwick Express, Great Northern, Southern and Thameslink, apologised for the disruption:
" With such extreme temperatures forecast, we have to run fewer trains, more slowly to keep services safe," she explained.
"I’d really urge our customers to think about what’s best for them and to travel only if absolutely necessary on Wednesday and Thursday.
“If you do have to catch a train, then consider travelling earlier or later in the day when it is cooler, or delaying your trip to later in the week.
"Please bring lots of water, wear sunscreen and a hat, and have a backup plan in case of disruption.
“And please do check before you travel on one of our websites as the situation could change along with the forecast."
Travel on Friday remains under review.