VolumeThermometer is a cTrader indicator that visualizes intra-higher timeframe (HTF) volume distribution using a heatmap. It aggregates tick volume data from lower timeframe (LTF) bars (e.g., M1) to construct vertical volume bins within each HTF candle (e.g., H4). The indicator highlights the Point of Control (POC) and Value Area (VA) lines, showing where the most volume is concentrated by price level. The current HTF candle is updated in real time, and the indicator automatically loads historical data for the visible chart range in small batches to optimize performance.

Key features include:
- Aggregation of tick volume from LTF bars.
- Division of HTF candles into price bins with volume assigned by price overlap.
- Color-coded volume bins indicating relative volume intensity.
- Display of POC and optional VA lines, with the ability to extend these lines forward.
- Customizable settings for bin detail, maximum HTF candles displayed, smoothing, opacity, and colors.
- Supports multiple markets including Forex, indices, commodities, stocks, and cryptocurrencies such as BTCUSD and EURUSD.

Users can monitor POC retests, VA rotations, and low volume node pass-throughs to analyze volume behavior within HTF candles. The indicator uses tick volume as a proxy, suitable for FX and CFD markets.