At many weights when REVERSERS are used properly there is no requirement for any cooling if you want to achieve minimum turnaround time.
For example on B738, 60T (representing a 43T ZFW, 2T fuel + 15T payload = >160 pax with a bag each!), calm winds, ISA day, DRY runway (no credit for reverse thrust in LDR taken):
Autobrake 2, idle reverse: Vref30 = 147 kts, Vat = 152 kts, Vbrakes = 149 kts => cooling 41 minutes, LDR = 2233m
Autobrake 3, idle reverse: Vref30 = 147 kts, Vat = 152 kts, Vbrakes = 149 kts => cooling 49 minutes, LDR = 1724m
Autobrake 2, idle reverse: Vref40 = 139 kts, Vat = 144 kts, Vbrakes = 141 kts => cooling 30 minutes, LDR = 2037m
Autobrake 3, idle reverse: Vref40 = 139 kts, Vat = 144 kts, Vbrakes = 141 kts => cooling 40 minutes, LDR = 1578m
Autobrake 2, 2nd detent reverse: Vref30 = 147 kts, Vat = 152 kts, Vbrakes = 149 kts => cooling 0 minutes, LDR = 2233m
Autobrake 3, 2nd detent reverse: Vref30 = 147 kts, Vat = 152 kts, Vbrakes = 149 kts => cooling 16 minutes, LDR = 1724m
Autobrake 2, 2nd detent reverse: Vref40 = 139 kts, Vat = 144 kts, Vbrakes = 141 kts => cooling 0 minutes, LDR = 2037m
Autobrake 3, 2nd detent reverse: Vref40 = 139 kts, Vat = 144 kts, Vbrakes = 141 kts => cooling 10 minutes, LDR = 1578m
In other words if you fly slower (flap 40 vs 30), brake less (auto brake 2 vs 3), use reversers properly and provided LDA is sufficient then it is possible to achieve those times.