Context: Warming up in very cold climates and maintaining an elevated body temperature prior to a race is challenging for snow-sport athletes. Purpose: To investigate the effects of active (ACT), passive (PAS), and a combination of ACT and PAS (COM) warm-ups on maximal physical performance in a subzero environment among snow-sport athletes. Methods: Ten junior alpine skiers completed 3 experimental trials in −7.2 (0.2)°C. The ACT involved 5 minutes of moderate cycling, 3 × 15-second accelerations, a 6-second sprint, 5 countermovement jumps (CMJs), and a 10-minute passive transition phase, while in PAS, participants wore a lower-body heated garment for 24 minutes. In COM, participants completed the active warm-up, then wore the heated garment during the transition phase. Two maximal CMJs and a 90-second maximal isokinetic cycling test followed the warm-up. Results: CMJ performance was likely (P = .150) and very likely (P = .013) greater in ACT and COM, respectively, versus PAS. Average power output during the cycling test was likely (P = .074) greater in ACT and COM versus PAS. Participants felt likely to almost certainly warmer (P < .01) and more comfortable (P = .161) during ACT and COM versus PAS. In addition, participants felt likely warmer (P = .136) and very likely more comfortable (P = .161) in COM versus ACT. Conclusions: COM resulted in significantly improved CMJ performance versus PAS while both ACT and COM led to likely improved 90-second cycling performance. Participants felt significantly warmer during ACT and COM versus PAS and likely warmer in COM versus ACT. Therefore, a combined warm-up is recommended for alpine skiers performing in subzero temperatures.