Possible Clues:

• Very hot day
• Hot day
• Really hot day
• One ironing negligently? It’s a hot day!
• Informally, a really hot day - it burns!
• Woman's after casual footwear, facing hot day
• Hard-hit line drive
• Very hot day; remarkable thing
• Match official sheltering companion in heat wave
• For a singer, 'One Fine Day'!