Crowds were already reduced in Bristol for Tuesday’s World Cup matches because of the heat.
A fourth victory for England on Wednesday would secure their progression through to the semi-finals with a match to spare.
West Indies, who knocked England out of the 2024 T20 World Cup, are also have three wins from three in this tournament but were pushed closed by New Zealand and Scotland. England beat the Windies 3-0 in a T20 series last year.
Dean will again deputise for skipper Nat Sciver-Brunt, who is not expected to play again in the group stage because of a calf injury.
Sciver-Brunt could return to training later in the week but will need another scan before being cleared to play.
“She’s been around the group and she’s tracking really well which is great,” Dean said.
“Having Nat on the field really provides us with a sense of confidence, the calibre of player that she is and the leader that she is.
“I’m ready to step up should it be needed but hopefully she’ll be back with us soon.”