England coach Hope Powell remains upbeat after watching her side draw 1-1 with Mexico in their opening game of the Women's World Cup.
Expected to start with a win, England were unable to break down stubborn opponents in the Wolfsburg Arena.
"We struggled a bit with the heat but no excuses - we will have to play better if we want to stay in this tournament," Powell told BBC Sport.
"We're disappointed that we didn't win but pleased we didn't lose."
England were rewarded for a strong start when Fara Williams found space in the box to head home Karen Carney's outswinging corner in the 21st minute.
But a long-range effort from Monica Ocampo caught out England goalkeeper Karen Bardsley and, despite toiling for a winner, England were forced to settle for an unsatisfactory point.
"The goal flew in, didn't it? But to concede the way we did was bitterly disappointing. We would have expected her [Bardsley] to have saved that," said Powell.
"We dominated up until that point and she was devastated to have let that goal in. It let them back into the game."
Powell allayed any concerns over the fitness of defender Faye White, who was substituted in the second half.
"Faye started to fatigue as the game went on, so we just took her off to protect her. We're happy with Faye's performance given that she has been out injured for a while," the England boss added.
England have a four-day break before facing New Zealand, who lost 2-1 to Japan in Monday's earlier game, on Friday.
Goalscorer Williams believes that is a game her team have to win.
She said: "We have to go into that game and get three points.
"We'll be concentrating between now and the New Zealand game on what we can do to beat them."
Williams made it 35 goals for her country but she was disappointed with the amount of other chances England let pass them by.
"We had lots of chances, mainly in the first half," she added. "Maybe if we were more clinical in front of goal we'd have come away with the three points.
"For maybe 60 or 70% of the game, we felt like we were in control.
"They had just one strike in the first half and, credit to her, it was a superb goal and something that you can't stop.
"We can't blame anything [like the heat]. Both teams had to play in really hot conditions today. It was difficult. The conditions were hard but both teams had to play in it."