England head into unknown territory at this World Cup when they face Norway in Miami on Saturday - playing in searing temperatures.

The Three Lions have been largely shielded from excess heat in North America.

Their schedule has included indoor matches in Dallas and Atlanta, and the three they have played outdoors - in Boston, New Jersey and Mexico City - have been in cooler, damper conditions.

That changes on Saturday for their quarter-final tie (kick-off 22:00 BST), which could be played in conditions the global players' union considers too dangerous for the game to go ahead.

Norway have played all but one of their matches outdoors - the exception being their last-32 victory over Ivory Coast in the air-conditioned Dallas Stadium.

Their 2-1 victory over Brazil on Sunday was played outside while New Jersey was under a US National Weather Service (NWS) extreme heat warning.

So who might be better prepared for the heat of Miami?

What is the weather forecast?

Put simply, conditions in Miami will be hot and humid.

While air temperatures are likely to sit about 33C (91F), once you add in the humidity, it will feel like about 41C (106F).

The National Weather Service has issued a heat advisory for the area on Saturday which warns that high temperatures and humidity may cause heat-related illnesses.

It is advising people to drink plenty of fluids, stay in an air-conditioned room and stay out of the sun.

Alongside the high temperatures, there is a risk of thunderstorms, especially near the start of the match, and a possibility of showers. Otherwise, sunny spells are expected.

In addition to how hot it will feel during the game, the Wet Bulb Globe Temperature (WGBT) will also sit around 29C to 32C.

The WGBT is an index which combines air temperature, humidity and surface temperature readings and is used by global sporting bodies such as Fifa to help keep players safe.

In its guidelines for playing in heat, external, players' union Fifpro says a WBGT above 28C should lead to the "delay or postponement of matches" until conditions are safer.

However, there is no suggestion that the game will not take place.

What temperatures have Norway and England faced?

While two of England's group-stage matches were played in the hotter Texas and Georgia climates, they felt the benefit of air-conditioned stadiums, where the temperature is set to a comfortable 21C.

The warmest the Three Lions have played in was 25C for the final group game against Panama, but that featured overcast skies.

July is Mexico City's wettest month of the year, so when England headed to altitude last Sunday they would have felt at home - 18C and rain.

The hot and humid weather in Miami will be a very different challenge.

Norway's tournament opener against Iraq, meanwhile, was played under clear skies and in a temperature of 25C.

There was rain and cloud during their games against Senegal and France, though they rested most of their first-choice players against Les Bleus.

After being indoors against Ivory Coast, Norway experienced oppressive conditions in the victory over Brazil. The temperature in New Jersey hit 31C in the shade, but on the pitch the heat and humidity would have made it feel far hotter.

Are England going to be ready for the heat?

England's initial base when arriving in the United States was, coincidentally, Florida.

Thomas Tuchel and his team spent 10 days in the area, playing warm-up games against New Zealand in Tampa and Costa Rica in Orlando.

The Three Lions then moved to their tournament facility in Kansas, where daily air temperatures are about 32-34C (90-93F).

That should help England cope with the heat.

Dr Lee Taylor from Loughborough University - a leading expert in elite athlete performance and the challenges of heat and altitude - told BBC Sport acclimatisation was crucial.

"That is the gold-standard method to protect players' health and performance," said Taylor.

"They've been getting those exposures into the players pretty consistently as they had two hot bases.

"So we're fairly certain those players are acclimated. They haven't been able to really test that in a game environment, but we're not too concerned because we know they've acquired those physiological adaptations."

Norway played their two warm-up matches against Sweden and Morocco in the cooler climes of Oslo and New Jersey respectively.

They are based in Greensboro, North Carolina, where they experiencing similar temperatures to the England squad.

"Norway have played four pretty warm games, and the one in New Jersey was particularly hot," Taylor said.

"I'd probably rather have the scenario that England have evolved through, based on the fatigue the Norway players have acquired."

What is the impact on the body?

England have used several methods of recovery at their training base in Kansas, including cooling tents

Many outdoor World Cup stadiums are open, with no roof or canopy. The Hard Rock Stadium is different, and looks more like a traditional European football ground.

That may keep the fans shielded from the elements but it prevents any breeze from reaching the pitch.

"It's a humidity trap," Taylor said. "There is no free-flowing air.

Sweating is king - it is the best way we can lose heat. We're highly efficient then. But in an environment that's got high humidity, with high water vapour pressure, there's nowhere for the sweat to go."

Fifa has introduced climate-controlled benches, the provision of water and electrolyte drinks, ice, cold towels, fans, mist and shade.

Another way of addressing the heat is by wearing phase-change ice vests - jackets with pockets for blocks of ice - before the match.

During hydration breaks and at half-time, a large towel that has been immersed in ice-cold water is more effective.

Whoever emerges victorious on Saturday must re-adapt for Wednesday's semi-final against Argentina or Switzerland. That game will be back indoors in Atlanta.

What does this mean for supporters?

Matches at the Hard Rock Stadium come with a risk of heat exhaustion and heatstroke.

After the first three fixtures, the Miami-Dade Fire and Rescue said it had received 38 heat-related calls at the stadium, with five requiring hospital treatment.

It has been more marked at the Fan Fest in the city, with the of City of Miami reporting 79 heat-related calls in one day on 23 June.

Fans have been urged to use shuttle stations, which have cooling sites, rather than walk all the way.

"The biggest issues come in what is often referred to as the final mile," said Taylor.

"This often has cordoning or protracted routes to manage crowd flow, and can be really difficult.

"The advice is pretty simple: seek shade, stay hydrated, have a refillable bottle and a wide-brim hat."

What have been the hottest games at the World Cup?

To underline what will await the teams, the two hottest games in the group stage were both in Miami.

For Uruguay's 1-1 draw with Saudi Arabia, the WBGT reached about 32.9C. This was surpassed by the 33C for Uruguay's 2-2 draw with Cape Verde six days later.

During the last-32 fixture in New Jersey, with temperatures of 32.22C, France's players tried to keep cool under the on-field sprinklers.

The warmest game of the tournament came last Saturday. Paraguay and France played their last 16-tie in Philadelphia at 37C. It felt closer to 44C thanks to the record-breaking heatwave that had developed across eastern states of the US.

One of the hottest World Cup games ever was in 1994 in Orlando, Florida, when temperatures hit 110 F (43.33 C) as Republic of Ireland played Mexico.

It will not quite be that warm in Miami on Saturday, but it still going to be testing for two countries from northern Europe. (BBC)

Update news