Typescript ‘any’ type error with dynamic array key

I’m getting the following error when trying to use a dynamic value for an array key.

Element implicitly has an 'any' type because expression of type '`faults_${string}`' can't be used to index type 'HeatsTable'.

export interface HeatsTable {
    heat_id: UUID
    start: number
    faults_1: string[]
    faults_2: string[]
    faults_3: string[]
    faults_4: string[]
  }

const fault = heatData[`faults_${runningId}`]; // Throws the above TS error

Using keyof HeatsTable works but causes an error on another page because it thinks faults could be a number. Is there another solution for this that I’m missing?