English Translation
The kettle must be boiling.
We hardly spell a “kettle” as 薬缶 in the twenty first century. Replace it with やかん. Wikipedia even avoids 薬缶 as an article name here.
I looked up the etymology. A kettle in Japan was used to brew herbal leaves for remedy. So, やかん is 薬（くすり）= medicine + 缶（かん）= metal can.