HotSpot Infrared Technology in Cricket — How Heat Detection Works
HotSpot uses infrared cameras to detect the friction heat left on a bat, pad, or glove when the ball makes contact. Learn how the technology works, why it was phased out of regular DRS use, and its current status in international cricket.
HotSpot is an infrared imaging system that detects the friction heat generated when a cricket ball makes contact with a bat, pad, glove, or other surface. Developed by BBG Sports, it was used in international cricket from 2006 onwards as part of the Decision Review System to help third umpires adjudicate caught-behind and LBW decisions with greater certainty.
How HotSpot works
Two infrared cameras are mounted at opposite ends of the ground, typically above the sight screens. They image the match continuously in thermal rather than visible light. When the ball strikes any surface — bat edge, pad, glove, or body — friction from the impact raises the temperature of that precise contact point by a fraction of a degree. The thermal camera captures this as a bright spot against the cooler background. Third umpires review the HotSpot footage frame by frame: a clear bright mark at the edge of the bat confirms contact; absence of a mark suggests the ball passed cleanly.
Strengths of infrared detection
HotSpot's key advantage is that it is entirely independent of sound. UltraEdge and Snickometer can be confused by ambient noise from pads, clothing, or footwork; HotSpot detects only physical contact and cannot be tricked by audio artifacts. For very thin outer edges — where the acoustic signal is minimal — a HotSpot mark can provide the decisive evidence that audio analysis cannot. It also works on pad contact, helping determine whether an LBW shout might have hit bat first (which would defeat the dismissal).
Limitations and declining use
HotSpot has significant drawbacks that led to its phased retirement from routine DRS use. The cameras are expensive to operate and require recalibration between sessions. More seriously, thin edges against a Kookaburra ball — used in most international matches — sometimes produce no detectable heat mark because the ball's lacquer does not generate enough friction. Conversely, a mark can appear from the ball grazing a batsman's sleeve or trouser seam without touching the bat. By the mid-2010s many Test series had dropped HotSpot from their DRS packages in favour of UltraEdge alone, due to both cost and reliability concerns.
Current status
As of 2026, HotSpot is available at some Test match venues but is not a mandatory component of the ICC's minimum DRS specification. Broadcasters in England and Australia still use it regularly for their coverage. When it is available, the third umpire may consider it alongside UltraEdge evidence; when it contradicts UltraEdge, the third umpire must exercise judgment. HotSpot remains more commonly used in men's Test cricket than in limited-overs formats.
Frequently asked questions
Why does HotSpot sometimes show a mark when there was no edge?
Friction from the ball brushing clothing, or a bat dragging across the turf, can leave a faint thermal mark. In high-humidity conditions, differential heating from sunlight on different parts of the bat can also create misleading patterns. These false positives are one reason HotSpot is used as supplementary evidence rather than as the sole basis for a decision.
Is HotSpot available in T20 Internationals?
Not routinely. T20Is generally use a lighter DRS package than Tests, and HotSpot is among the first components dropped when the full system is not available. Most T20 DRS decisions at ICC events rely on HawkEye (for LBW) and UltraEdge (for edges) without HotSpot.
Who pays for DRS technology at a cricket match?
The host cricket board or broadcaster typically funds the technology package. The ICC mandates DRS for all ICC events but leaves some discretion over the specific components to bilateral host boards. This is why the DRS package can vary from series to series.