Under way at Cheltenham where Hampshire are batting. Felix Organ gets a couple off Ryan Higgins' opening over.

Now Ian Holland will face Tom Price at the other end.

Hampshire's team is very different from the one that won the T20 Blast, but they do include their star four-day bowling trio of Keith Barker, Mohammad Abbas and Kyle Abbott.

Unsurprisingly, Somerset chose to bat first after winning the toss.

There is no Peter Siddle in their seam attack for this game, South African Marchant de Lange takes over, while Yorkshire's batting line-up is bolstered by the return of Harry Brook.

Jordan Thompson bowls the opening over, which includes a fortunate inside edge for four by Matt Renshaw.

Essex are in great form at the moment, having won their last three Championship games - but are they capable of inflicting a first defeat on the Division One leaders?

Alastair Cook and Nick Browne open, as usual, for Essex, who welcome back England Lions seamer Sam Cook, while Surrey have West Indies fast bowler Kemar Roach back in their side.

Image source, Getty Images

The mercury is pushing 100 degrees, pitches are like roads and outfields as parched as the fairways at St Andrews. Surely winning the toss this morning would have been a no-brainer - BAT.

Obviously, Warwickshire's Will Rhodes must know differently as he has opted to bowl.

Let's hope they don't have a day like Nasser Hussain at The Gabba in 2002. He infamously asked Australia to bat first in the first Ashes Test and the home side ended day one 364-2.

Image source, Getty Images

The dust is still settling on that incredible finish to Saturday's T20 Blast final with Hampshire grabbing a one-run victory over Lancashire.

But now the T20 stuff is done, Hants can throw all their attention now at the County Championship and having the best season in their history.

It's 49 years since the last of their two titles and no side has won more than their six matches this season.

They trail leaders Surrey by 15 points, but they will hope for victory this week against bottom side Gloucestershire.

No matter the temperature our BBC 5 Live Sports Extra and local radio commentators are in position to bring you ball by ball coverage of today's seven matches - but let's hope they have a supply of water and ice creams/lollies to keep them going through the day.

Choose a match from the promos at the top of the page and we will keep you apprised of events at the other grounds with regular text updates.

There will only be 90-minute sessions at Cheltenham and Northampton today because of the extreme heat.

The four teams involved will then try and make up the 'lost' time over the final three days.

Division One

Cheltenham: Gloucestershire v Hampshire

Hampshire won toss and will bat

Northampton: Northamptonshire v Lancashire

Northamptonshire won toss and will bat

Taunton: Somerset v Yorkshire

Somerset won toss and will bat

Kia Oval: Surrey v Essex

Essex won toss and will bat

Edgbaston: Warwickshire v Kent

Warwickshire won toss and put Kent in

Division Two

Derby: Derbyshire v Nottinghamshire

Nottinghamshire won toss and will bat

Lord's: Middlesex v Sussex

Middlesex won toss and put Sussex in

Image source, Rex Features

You can tell it's a little bit hotter than normal when Middlesex put out a statement which says the following:

"MCC has advised us that the dress regulations in the Pavilion will be relaxed on Tuesday 19 July. Gentlemen in the Pavilion that day will not be required to wear a jacket, although MCC will still require Gentlemen to wear ties. Spectators should also adhere to the usual dress regulations on trousers and shoes, as stipulated below."

In case you are not familiar with the dress code relating to trousers and shoes at Lord's, for Gentlemen it's "tailored trousers, chinos, corduroys or moleskin trousers" and "formal shoes with socks which cover the ankle."

Ladies can wear a "dress, skirt or tailored trousers with a top or blouse, or other clothing that is appropriately formal. Formal shoes, boots or sandals must be worn."

There has been a change of skipper at Wantage Road. Tweet us at #bbccricket, Northants followers, and let us know what you make of the latest captaincy development.

Meanwhile, India's Cheteshwar Pujara will captain Sussex at Lord's after Tom Haines suffered a broken hand last week.

At Derby, Leus du Plooy will skipper the home side against Notts, in place of Billy Godelman.

Here's how the top of Division One and Two look following last week's Championship matches.

Image source, .

Image source, .

Hot - as these two BBC Weather tweets make very clear.

Former US president Ronald Reagan is reported to have once said: "When you can't make them see the light, make them feel the heat."

County cricketers at seven grounds will certainly be feeling it today on what is expected to be the hottest day of this, or any other, year since records began.

For those about about to spend an entire day toiling the field, you have our sympathy. Don't forget the heavy duty sunscreen.

Welcome to our coverage. Play starts at 11:00.