I was with my friend all day yesterday in her house as our kids were having a post Xmas playdate. We all tested before meeting and all negative. She messaged me this morning and told me she woke up feeling tough so did an LFT which was positive. Awaiting her PCR but likely she'll be positive as she has symptoms now too. What are the chances of transmission? Indoors all together for about four hours. Incidentally today I feel exhausted.