Runners and spectators at this years Great North Run are being advised to take extra precautions as warm weather is expected over the weekend.
Water and ice blankets are among the supplies being lined up to help people deal with the conditions.
St John Ambulance teams will be along the 13.1 mile route to provide medical assistance and supplies to runners dealing with weather-related issues.
Dr Hannah Pool of the volunteer organisation said this can even include overheating.
She said: "As your body heats up it can sometimes make you very unwell.
"If someone becomes unwell when they've overheated it's really important we cool them very rapidly and the things we have in place to be able to do that are fans, having ice so we can cover people in icy water, blankets soaked in icy water and those really simple measures effectively cool people."
Around 450 St John Ambulance volunteers will be deployed along the length of Sunday's route as well as at the finish line.
The team are expecting many of the usual race day problems including cramps and blisters, however, they are urging those taking part not to underestimate the power of the heat.
Top tips for running in warm weather includes:
- Drink water when you're thirsty
- Wear sun protection. Put on suncream and a hat to prevent sunburn or sunstroke.
- Enjoy the atmosphere rather than aiming for a personal best
- If you feel unwell, stop running and seek medical help
Experienced Great North Runner Matthew Stephenson is taking the advice on board.
He told ITV Tyne Tees: "It's obviously a bit more of a challenge, it does tend to zap your energy a lot more, maybe cloud your judgement and what pace you're trying to run at.
"I'll be bringing a bottle of water with me and I'll be taking plenty of water on at the hydration stations that are dotted around."
He added: "I'll be wearing a hat and if I feel I need to manage my pace a little bit more, I'm happy just to drop that pace a little bit and just enjoy the day."
For those organising the race, measures to ensure that participants safely cross the finish line are part and parcel of preparations.
Nigel Gough, from the Great Run Company, said: "Clearly we've been monitoring the weather for days now. It's something that we have as part of the planning process.
"We'e got the standard procedures in terms of six drinks stations, we've got three extra showers, we've got additional showers at our drinks stations, we've got welfare pickup points. These are all planning measures that we put in every year."
The weather is one of many factors that will come into play this Great North Run weekend. The message from volunteers and organisers is not to underestimate it.
What is the weather forecast on Sunday?
Temperatures are expected to be very warm and hot on Sunday, with the outbreak of some heavy and potentially thundery showers.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know...